This literature review was produced by the Ummatics Institute’s Political Unification Academic Working Group in connection with its 2025 workshop on this topic. See the Call for Papers here.

 

Political unification has attracted attention in political science and international relations literature in the past, with interest waning in more recent times. Scholars of these disciplines have offered diverse explanations and frameworks for understanding this phenomenon. “Political unification” refers to the process by which sovereign states voluntarily unite to form a larger sovereign political entity governed by shared institutions. This form of unification typically extends beyond nation-state borders. It brings together resources, collective decision-making authority, and emphasizes the shared identities of its constituents to pursue common objectives such as improved security, economic and social integration, and political stability. Although there is broad agreement on the general definition of this concept, scholars employ different terminology to describe it. Furthermore, significant disagreements remain on what drives unification processes and what conditions and variables are most critical for its success.

This short literature review will first briefly touch upon the relevance of political unification today before accounting for different terminology scholars have used to describe it. It will then examine the main theoretical frameworks of political unification, highlighting their distinctions and accounting for variables that influence the sustainability of political unification once it has occurred. The review will then provide some examples of the literature that has examined case studies of political unification. Finally, it will conclude with a section that identifies gaps in the literature and potential areas for further research.

 

Why Political Unification?

Before exploring the literature in question, it is important to note that voluntary political unification remains relevant today. The recent case of political unification between Mali, Burkina Faso, and Niger, who signed a confederating treaty in July 2024, recalls numerous unification attempts in the past decades between Arab and African states. Going further back, similar attempts occurred in nineteenth century Latin America. However, seldom is the current attempt in the Sahel framed within the broader historical cases of voluntary political unification, which were post-colonial efforts aimed at political assertion on the international stage. They were attempts of unification undertaken before international organizations and multilateralism became popular forms of collective state action and cooperation.

Mohamedou Ould cites at least eighteen attempts between Arab states to merge into one state between the 1940s and 1970s (not including the United Arab Emirates which was born out of similar attempts that could have included Bahrain and Qatar who later opted out).¹ More recently, after the Arab Spring started, Saudi Arabia and Bahrain floated the idea of a merger between the two states. The potential merger was seen by observers as a gateway for Arab Gulf state mergers.² In Africa, examples of unification include Senegambia, a merger of Senegal and Gambia that lasted from 1982-1989. Present-day Tanzania is the product of Tanganyika and Zanzibar uniting in 1964. The United States, Germany, and Italy are other successful cases of unification.

Today there are numerous failed or weak states in the Umma whose policy makers could benefit from studies on political unification. Sudan, Libya, and Yemen itself could benefit from its North-South unification experience in 1990. Somaliland and Somalia are in a comparable situation. In other words, research on political unification will not merely enrich political science literature but will also be informative to policy makers desiring closer interstate ties or actual political unification.

The literature on voluntary political unification remains sparse with plenty of room for advancements and contributions. As Ryan Griffiths notes, voluntary political unification is an “important phenomenon and our theoretical understanding of the matter remains incomplete.”³ Moreover, the persistent and unwavering desire for ummatic unity among the Muslim masses is far too obvious to ignore and could catalyze attempts of voluntary political unification.⁴ Prior knowledge on political unification could help predict, understand, and direct the future of such attempts.

 

Nomenclature

There are various terms used in the literature that describe the phenomenon of political unification. Amitai Etzioni for example refers to political unification as “supranational unification.”⁵ Karl Deutsch prefers the notion of  “amalgamated security communities” to refer to cases of two or more states merging, as opposed to “pluralistic security communities,” in which countries cooperate to achieve security without merging to form one sovereign entity. Ole Waever uses  “political integration” and regards the founders of “integration theory” as Ernst Haas, Karl Deutsch, and Amitai Etzioni.⁶ These scholars pay particular attention to the concept when examining European integration. Etzioni himself uses the term “halfway integration” to refer to entities like the European Union whose constituent states have full or near full sovereignty on certain matters and policies while losing full or near full control to a supranational authority on other important matters.⁷ This is contrary to “full integration” which refers to political unification proper as defined above. Thus, it is crucial to note how these labels and concepts are closely related and sometimes used interchangeably.

Labels aside, one finds considerable disagreement among leading scholars with regards to what drives the process of political unification and the variables most critical for its success. Ernst Haas views it as an incremental process led by economic integration, such that cooperation in economic sectors paves the way for political unification. Karl Deutsch, on the other hand, emphasizes security, arguing that unified entities emerge from a shared need for defense, resulting in “amalgamated security communities.” Amitai Etzioni’s primarily normative approach emphasizes the importance of a “political community” in which citizens of multiple states prioritize a shared, transnational identity over their national identities. In contrast, William Riker frames unification as a bargain, positing that states unite based on mutual interests and that unification succeeds when all parties see tangible benefits. These different theories about what causes and sustains political unification will be explored in more detail below.

 

Theories, Frameworks, and Preconditions

The theories and frameworks of political unification in the literature can be classified into several perspectives mirroring existing schools of thought. Neo-functionalist theories, as exemplified by Haas, emphasize the spillover effect of economic integration into political unification. Realist perspectives, like Riker’s, highlight security concerns and power dynamics as drivers of unification. Liberal approaches, represented by Deutsch, stress shared values and communication in creating “security communities.” Finally, constructivist frameworks, as seen in Etzioni’s work, underscore the importance of shared identity and norms in the unification process. These diverse perspectives, outlined in greater detail below, offer complementary and sometimes competing explanations for the complex phenomenon of political unification.

In exploring these theories of political unification, it becomes evident that its process is shaped by a multitude of factors, like institutional frameworks, social identities, and the material interests of the constituent units. Ernst Haas’s neo-functionalist theory provides a foundational understanding of political integration. Haas argues that unification occurs through a process of “spill-over,” where cooperation in one sector of the economy or society creates pressures for further integration in related areas.⁸ This model suggests that supranational institutions are crucial in facilitating deeper integration by generating dependencies that encourage subsequent unification. Haas’s theory emphasizes the importance of these institutions in managing and propelling the integration process, reflecting a vision of a dynamic, evolving political landscape.

Building on earlier work, Haas extends his analysis of how historical experiences of political and cultural unity do not necessarily guarantee future integration.⁹ He notes that while the memory of past unity can influence present efforts, it is not a sufficient cause for re-unification on its own. Instead, he highlights the role of external stimuli, such as creative crises or traumatic events, in catalyzing the integration process. For example, the two world wars in Europe functioned as significant triggers for political and economic unification. Haas identifies three modes of conflict resolution that indicate the direction of integration: a) accommodation based on the minimum common denominator, where agreements reflect the least cooperative partner’s concessions; b) accommodation mediated by an independent body which splits the differences; and c) accommodation through upgrading common interests, which involves institutionalized mediation and parliamentary diplomacy. These modes illustrate various pathways to achieving political unity and highlight the role of institutional mechanisms in facilitating integration.

In another seminal work, Haas and Schmitter examine whether economic integration consequentially leads to political unification. They develop and apply a framework to several regional integration attempts, like the European Economic Community (the predecessor of the EU), the East African Common Market, the OECD, and LAFTA, to examine this hypothesis and conclude that indeed economic integration does eventually lead to political integration.¹⁰

The hypothesis that economic integration leads to political integration has been contested by other scholars. Søren Dosenrode’s critique of Haas’s theory introduces important concepts such as “spill-back” and “spill-around” to address the often-non-linear nature of integration.¹¹ Dosenrode challenges Haas’s optimistic view of integration and argues that the process is not always smooth or predictable. “Spill-back” refers to the phenomenon where integration in one area can lead to setbacks or conflicts in other areas, while “spill-around” describes how integration can generate unintended consequences or disruptions in neighboring regions. This critique highlights that integration processes are often more complex and fraught with difficulties, with a range of factors introducing obstacles that hinder the seamless progression Haas envisioned.

Regarding the generalizability of Haas’s framework, Joseph Nye offers a much earlier and extensive critique by examining the challenges faced in applying European integration models to other regions.¹² Nye argues that the applicability of these models is often complicated by factors such as over-politicization and ethnic divisions, which can impede the integration process. His analysis underscores the need to consider unique regional contexts when applying integration theories, emphasizing that different regions may face distinct challenges and require tailored approaches to integration. Nye criticizes Haas and Schmitter’s idea that economic and political integration could be treated as part of a continuum. He also criticizes the framework of their study for consideration of insufficient variables, in particular the lack of exogenous factors, and for not stating the relationship between the variables. Nye highlights that not all the variables considered have equal weight and suggests that elites are the most important variable.

Karl Deutsch’s work enriches the discussion by focusing on the role of shared values and communication in political integration. Deutsch conceptualizes integration as creating stable expectations of peace among participating units, even in the absence of fully merged political institutions.¹³ As mentioned above he introduces the idea of a “pluralistic security community,” which is achieved through various integrative processes. Deutsch identifies political amalgamations—where political units voluntarily merge—as a foundational method for achieving integration. However, he notes that successful amalgamation is more likely to produce a stable security community when a common identity is cultivated. Key processes identified by Deutsch include psychological role-taking, where members develop a “we-feeling” through individual experiences, indoctrination, and assimilation, which involves aligning cultural and value systems. Additionally, he emphasizes mutual interdependence through economic and specialized interrelationships leading to deeper integration, and mutual responsiveness to each political unit’s needs. Finally, Deutsch discusses simple pacification, entailing the renunciation of war and disarmament. He argues that the stability of a security community depends on balancing integration loads—demands on decision-making and resources—with integration capabilities—habits and institutions for maintaining peace.

In more recent work, Deutsch and his colleagues revisit and expand upon the notion of security communities, emphasizing that integration involves ongoing processes and dynamic interactions rather than static conditions.¹⁴ They argue that achieving and maintaining a security community not only requires initial agreements but also sustained efforts to foster a shared identity and cooperative norms. This contemporary analysis reaffirms Deutsch’s earlier findings while adapting them to contemporary contexts, illustrating the evolving nature of political integration.

While Deutsch builds on Haas’s framework by emphasizing the role of shared identity and norms in sustaining unified polities, Amitai Etzioni goes further by placing identity and the communitarian nature of unified polities at the very core of the political integration process.¹⁵ Etzioni argues that integration cannot be fully understood without considering the shared values, emotional bonds, collective identity, and normative commitments that underpin political or social unification. Etzioni’s approach posits that groups or political entities typically move through divergent paths before eventually converging into a higher-level union. This process involves several stages of negotiation and adaptation, where initial agreements are reached within smaller sub-groups before these agreements integrate at a higher level. Etzioni’s dialectical approach emphasizes that unification is not a linear process; rather, it entails navigating conflicts and contradictions to reach a synthesis. This perspective highlights the iterative nature of political unification, which progresses through a series of adjustments and reconciliations. Etzioni’s framework distinguishes between distinct types of unions—mono-sectoral versus multi-sectoral—where multi-sectoral unions are seen as more complex and challenging but potentially more rewarding in terms of integration.¹⁶

Bruce Cronin extends Etzioni’s thesis by examining the history of international politics. Cronin hypothesizes that the nature of transnational identities among the constituent units of a unified polity determines its stability and shapes its fundamental structure—specifically, the relationship between the central authority and the units, as well as the interactions between the units.¹⁷ Cronin argues that a shared transnational identity, built on common characteristics and positive interdependence, is crucial for creating cohesive political units. His work highlights the importance of building a common identity that transcends national boundaries to facilitate deeper political integration.

Departing from the liberal institutionalist frameworks of Haas and Deutsch, as well as the constructivist approach of Etzioni, Riker presents a realist perspective on political unification. Riker’s work draws heavily from rationalist and realist logics, providing a distinct framework for understanding the formation and stability of supranational or politically unified entities.¹⁸ His theory posits that political unions emerge primarily from a “federal bargain,” a pragmatic and strategic agreement among political elites driven by considerations of security and expansion. At the core of his argument lies a realist perspective that views international relations as primarily shaped by power politics, competition, and the pursuit of self-interest. From this standpoint, Riker contends that political unification arises not out of idealism or a shared vision of unity but out of necessity. The driving force behind the federal bargain is actual or anticipated external military threat. Political elites, recognizing the need to enhance their collective security, opt to form a federation as a means of survival in an otherwise anarchic international order.

Additionally, Riker’s argument operates from a rationalist perspective, wherein political actors are assumed to be rational agents striving to optimize their benefits while minimizing costs. Riker perceives the federal/unification bargain as a rational choice favoring centralization because it offers the constituent units greater protection and benefits compared to those attainable independently. For the political elites negotiating this bargaining process the trade-offs involved, such as ceding a degree of autonomy in exchange for centralized authority, are weighed carefully based on the anticipated benefits, such as enhanced security, economic opportunities, and political stability. This rationalist approach explains why federations often arise in contexts where military threats or expansionist ambitions necessitate enhanced coordination and centralization of power. Riker’s notion of political unification is thus tied to the logic of power, as federations create a balance between the central government and the constituent units, enabling better coordination in response to external challenges. For Riker, the success of a federation lies in its ability to manage this delicate balance, ensuring that the central government has enough authority to maintain security without undermining the autonomy of its constituent members.¹⁹

The literature also explores the impact of specific variables on political unification, with different scholars focusing on different variables. Arend Lijphart focuses on cultural diversity as a determinant of the sustainability of a unified polity.²⁰ Lijphart finds that most theories (at the time of his writing) consider cultural homogeneity, especially that of political culture, a prerequisite for political integration. However, theories by Haas and Etzioni, as well as theories of unification in the federalism literature do not agree with this contention. Lijphart refers to these latter theories which emphasize elite cooperation to counteract cultural fragmentation as political stability theories. He then introduces the concept “consociationalism” as a strategy to manage cultural diversity and keep all minorities invested in the political system.

Ryan Griffith contributes to the research on culturally specific variables by examining the role of linguistic homogeneity in fostering political integration. Using a large-N (quantitative) analysis of cases from 1816 to 2001, Griffiths evaluates two primary hypotheses: that external security threats are a driving force behind unification, and that linguistic homogeneity is a critical condition for its success. His findings challenge the views of Riker, who emphasized security threats as the primary motivator for unification. Instead, Griffiths demonstrates that while security threats can act as catalysts, linguistic homogeneity plays a more significant role by facilitating effective communication and fostering a shared national identity.²¹ In contrast to Riker’s theory, Griffith’s study demonstrates that security threats are not always necessary for unification, as evidenced by cases such as Yemen and Tanzania, where integration occurred in the absence of significant external threats.

Joseph Parent’s work complements all of the above perspectives by focusing on the conditions under which voluntary political unification occurs.²² Parent’s extensive study identifies and analyses three key factors which determine when and how political unification occurs: opportunity, fortune, and virtue. Opportunity refers to background conditions necessary for unification, such as security threats that create mutual vulnerabilities. Fortune, much like the “creative crises” described by Nye and Haas, refers to a public crisis that reveals deficiencies in the current order and demands extraordinary political action to address them. Virtue requires the role of political entrepreneurs who persuade audiences that unification will solve their problems. Parent’s analysis of cases such as the United States and Switzerland, as well as failures like Sweden-Norway and Gran Colombia, highlights how different conditions influence the success or failure of political unions and the importance of these factors in shaping the outcomes of unification efforts.

 

Sustaining Political Unification

Having explored the theoretical frameworks that explain the motivations and conditions that bring about political unification, we now shift focus to the question of what sustains these political entities in the long run. While the previous section focused on the processes through which states and actors enter political unification arrangements and the underlying rationale guiding this behavior, this section will delve into the literature discussing the determinants of success and failure of specific political configurations that emerge from these unifications. Here, the emphasis lies on the long-term survivability of politically unified entities, particularly through federalism and other governance structures, along with the factors that contribute to their longevity or transience.

The literature on the long-term stability and success of political unifications can be broadly divided into two distinct categories. The first emphasizes the role of elite dynamics and communication networks, prioritizing non-institutional factors as essential underpinnings for maintaining the institutional framework of political unity. The second focuses on institutional design and the political structures that emerge from unifications, such as federalism or consociationalism, examining the conditions that sustain or weaken them over time. Consequently, research on the sustainability of political unifications intersects with broader inquiries into the design and durability of political institutions.

Ernst Haas, in this regard, argues that elite socialization is fundamental to the long-term stability of political unions. He emphasizes that supranational institutions must gradually gain authority over national governments, functioning as conflict management mechanisms that encourage cooperation among member states. Haas underscores the importance of functional integration, that is the deepening of economic and political cooperation, as well as the formation of shared identities among both elites and the broader population. According to Haas, political integration becomes self-reinforcing as supranational institutions make decisions that are difficult for national governments to reverse, further entrenching loyalty to the union.²³

Karl Deutsch complements Haas’s ideas but focuses more on the social and communication aspects of political integration. For Deutsch, the density of communication networks and the volume of social transactions between member states are critical to fostering a sense of community and shared identity.²⁴ This interconnectedness leads to mutual trust, which reduces conflict and supports integration. Deutsch argues that the more elites and citizens engage in sustained interactions, developing emotional bonds and shared values, the stronger the sense of collective identity becomes, enhancing the survivability of political unions.

Etzioni expands on these ideas by emphasizing the critical role of shared values and social cohesion. Like Deutsch, Etzioni highlights the importance of social bonds, but he adds a moral dimension, arguing that communal identity and shared norms act as the social glue necessary for enduring political unification. He further stresses the need for legitimate authority and inclusive governance structures that ensure fair representation for minority groups and mechanisms for conflict resolution within the union. Like other scholars, for Etzioni, a careful balance between central authority and local autonomy is essential: excessive centralization can lead to resistance, while insufficient central authority may erode unity. Thus, his communitarian approach underscores the integration of moral values, social participation, and responsive governance as key to the survivability of political unification.²⁵

Together, Haas, Deutsch, and Etzioni provide complementary perspectives that emphasize the importance of elite integration, communication networks, and shared moral values in fostering stable and enduring political unions.

With regards to the structural dynamics of political unifications, Riker focuses on federal systems and the distribution of power between central and regional governments. He argues that the stability of federations hinges on the balance of power: a strong central government is necessary to maintain order, while regional governments must retain enough autonomy to manage local affairs. This autonomy prevents the central government from overreaching and creates a sense of ownership and satisfaction among regional actors. Riker also identifies the role of integrated party systems in maintaining stability. In federations where political parties operate at both the national and regional levels, there is a bridging of interests between local and national concerns, which enhances coordination and mitigates conflicts. This dual-level integration helps federations endure over time, as political parties act as channels of communication between different levels of government.

Contributing to structural variables that sustain unification, Jenna Bednar’s research explores the complexities of federal constitutional design and the challenges that federations face in terms of compliance, adaptability, and safeguards. Bednar argues that the distribution of authority in federal systems is more than a static balance of power; it is a dynamic instrument that can be calibrated for social benefit.²⁶ She highlights the inherent tension between strength and flexibility in federal systems, noting that successful federations must have mechanisms to enforce compliance with agreed rules, managing opportunistic behavior, and adapting to new circumstances. Bednar identifies institutional safeguards as essential for preventing actors from exploiting weaknesses in the system, emphasizing that effective federations require not just authority distribution but also mechanisms for upholding commitments and managing conflicts.

Building on these insights, Riker and Lemco argue that centralized federations tend to be more stable because they have a greater capacity to coordinate among their constituent units.²⁷ This perspective contrasts with the view that decentralized federations often face challenges in coordination and collective decision-making. The work of Erk and Anderson introduces a further complication in this debate: the “paradox of federalism.” They argue that while federal institutions are often designed to manage ethnic divisions, they can unintentionally entrench and perpetuate those divisions. By granting self-rule to ethnic groups, federalism may “freeze” ethnic distinctions, making it harder for societies to achieve greater integration. This tension underscores the complex relationship between federalism and ethnic conflict, where the very mechanisms meant to ensure stability may exacerbate fragmentation.²⁸

A related notion here is that of “ethnofederalism,” which refers to a federal system of government where the constituent units are defined along ethnic lines. It is a way to manage ethnic diversity within a state by granting self-rule to different ethnic groups. Liam Anderson contributes to the research on ethnofederalism by challenging the notion that such systems are inherently unstable.²⁹ He contends that while most political scientists argue against ethnofederalism, there is considerable disagreement among practitioners, which indicates the need for further investigation.

Anderson notes that political scientists rely on three high-profile cases to argue against ethnofederalism: the Soviet Union, former Yugoslavia, and Czechoslovakia are used to conclude that ethnofederalism promotes secession and disintegration. Anderson argues that these cases fit a narrower definition of ethnofederalism which if otherwise expanded could show numerous cases where ethnofederalism was successful. He also rhetorically asks, if not ethnofederalism, what is the alternative? Anderson suggests that when carefully designed, ethnofederal systems can outperform unitarist alternatives in managing deeply divided societies. The success of these systems, he contends, hinges on their ability to foster inclusive national identities rather than reinforcing ethnic divisions. Notably, there is much more literature on ethnofederalism requiring further research and investigation in its relation to political unification.

Filippov, Ordeshook, and Shvetsova make a significant contribution to the discourse on constitutional design and federal stability by emphasizing the limitations of relying only on constitutional provisions to ensure stable federal systems.³⁰ They argue that even with robust constitutional constraints on the powers of the federal government or central authority—what they term the “first level” of constitutional design, or “constitutional constraints on federal bargaining”—these measures are insufficient on their own. Instead, they propose a multi-tiered framework of constitutional design. At the “second level,” institutional rules regulate political competition among elites across various levels of government. These rules establish the broader principles of government structure—whether the system is presidential, parliamentary, federal, or unitary—shaping how political power is organized and contested. The key objective at this level is to align the incentives of political elites, ensuring that intergovernmental bargaining promotes compromise rather than disruption. Finally, the “third level” focuses on the implementation of the second level through “institutional devices” that foster political party integration. These mechanisms, such as locally coordinated elections or electoral oversight spanning multiple levels of government, serve to strengthen connections across constituent units. The authors underscore that without these incentive structures, federal systems are prone to instability, as constituent units may engage in non-cooperation or shirk their responsibilities, jeopardizing the cohesion of the federal arrangement.

McGarry and O’Leary provide an example of a nuanced argument on the federalism debate, arguing that federations are more likely to succeed when they accommodate complementary identities within the population. Citizens of the federation must feel allegiance both to the federal state and to their national or regional identities. They underscore the stabilizing role of a dominant nationality, or “Staatsvolk”, especially when this dominant group is geographically dispersed. Additionally, they highlight the importance of consociational power-sharing arrangements as a mechanism for ensuring minority retention and preventing secession, as these arrangements allow different ethnic or national groups to share political power.³¹

Figueiredo and Weingast explore the delicate balance between national authority and regional autonomy in federal systems. They assert that for a federal arrangement to endure, the benefits of membership for constituent units must surpass the costs associated with remaining part of the federation. Their most notable contribution lies in their emphasis on the need for robust mechanisms to detect non-compliance and impose penalties for shirking responsibilities. Their analysis highlights two critical factors in sustaining federal stability: the likelihood of detecting non-cooperation and the severity of the penalties imposed. Together, these factors ensure that constituent units have strong incentives to adhere to collectively agreed-upon rules, thereby reinforcing the cohesion and functionality of the federal system.³²

Together, these scholars offer a comprehensive if non-exhaustive view of federalism’s complexity, benefits, and challenges. While there are many more aspects of federalism to explore, the above research highlights how the balance between central authority, regional autonomy, ethnic diversity, and institutional design present a significant challenge to the stability and success of federal systems.

 

Case Studies

In recent decades, numerous cases of political unification have emerged, some more successful than others, offering a wealth of practical lessons. These cases have served as valuable testing grounds for scholars to create and refine their theories and frameworks. By analyzing a diverse array of case studies, researchers can uncover previously overlooked patterns of political behavior, explore varying motivations, and consider the unique political contexts and historical narratives that have shaped these attempts. Such insights hold significant potential for informing future efforts aimed at achieving political unification.

This section will review the literature that examines some of these case studies in depth. From the challenges faced by pan-Arabism to the aspirations and obstacles encountered by Latin American and African integration movements, these examples provide rich material for understanding the dynamics of political unification and its complexities.

Malik Mufti examines the paradox of pan-Arab initiatives that continued despite their significant failures.³³ His central argument is that the drive for unity was often rooted in domestic and foreign imperatives that influenced governments pursuing integration. Malik introduces the concept of “defensive unionism,” the phenomenon of governing elites, facing domestic instability, seeking pan-Arab unity to consolidate their power and legitimacy. This strategic engagement served to neutralize domestic opposition and secure external support. Mufti supports his arguments through the case studies of Iraq and Syria’s unification attempts in the 1950s and 1960s, arguing that political unification attempts were primarily policy driven. He does not deny the ideological sentiment that promoted pan-Arabism but finds it insufficient to explain Syria’s numerous attempts to unify, while Jordan, which also shared these sentiments, made no such attempts. Mufti’s work provides a critical framework for understanding some motivations behind regional integration.

Echoing Mufti’s analysis, Elie Podeh contributes to the discourse on pan-Arabism by examining its ideological foundations and how they interacted with the interests of ruling elites in the Arab world.³⁴ He argues that while pan-Arabism initially aimed to foster unity and collective identity among Arab states, it was instead used by elites as a tool for political manipulation. This transition from ideological aspiration to strategic exploitation illustrates the ways in which ruling regimes selectively appropriated pan-Arab rhetoric to bolster their legitimacy while simultaneously suppressing dissent and diverting attention from domestic grievances. By highlighting this discontinuity between pan-Arab ideals and the political realities imposed by elites, Podeh underscores the significant role that elite interests play in shaping the trajectory of politically unified entities. His critique illuminates how the aspirations for regional unity became entangled with the self-serving mechanisms of those in power, contributing to widespread disillusionment among citizens who perceived these initiatives as lacking genuine commitment.

Transitioning to a focused case study of political unification within the Arab context, Gerd Nonneman provides a detailed analysis of Yemen’s unification.³⁵ He contends that earlier efforts to merge North and South Yemen often failed due to unrealistic expectations and an absence of compelling practical incentives for unity. Nonneman identifies ideological divergences and external influences—such as Saudi support for North Yemen and Soviet backing for Aden—as significant barriers to earlier merger initiatives. He further highlights the conditions that ultimately enabled Yemen’s unification in 1990, emphasizing the interplay of internal conflict and external pressures. He argues that these factors can serve as either catalysts or impediments to unification. This case study underscores the complex dynamics at play in efforts to achieve political unification and the significance of both domestic and international contexts in shaping their outcomes.

Shifting to Pan-Africanism, Guy Martin critiques the initial aspirations of Pan-Africanist leaders, highlighting their gradualist approach that resulted in the loosely structured Organization of African Unity (OAU). He argues that the reluctance of newly independent African leaders to relinquish sovereignty and the divide-and-rule tactics of Western powers were significant factors that contributed to the failure of African unification efforts.³⁶ This critique resonates with the challenges faced by other regions, illustrating a common struggle among leaders to balance national interests with broader collective goals. By juxtaposing the trajectories of pan-Africanism with those of pan-Arabism and Latin American integration, Martin highlights the ongoing challenges of fostering regional unity amidst competing national interests and external pressures.

Joseph Nye made an earlier valuable contribution on African cases. Nye emphasizes that economic cooperation among East African countries did not inherently lead to political unity,  arguing that this disconnect stemmed from conscious political decisions influenced by the ideologies and national interests of the region’s leaders.³⁷ While there was a collective aspiration toward pan-Africanism, characterized by goals of economic independence and dignity for African nations, the divergence in national priorities and interpretations of these ideals among the leaders hampered integration efforts. The leaders’ varying commitments to the concept of federation, coupled with local ambitions, ultimately revealed that economic ties alone were insufficient for achieving political cohesion.

Nye’s analysis shows that successful regional integration requires more than just economic collaboration; it necessitates a strategic alignment of political will, where leaders actively engage in shaping policies that foster unity while addressing their distinct national interests. The failure to harmonize these elements was a pivotal factor in the breakdown of the East African Federation, illustrating the complex interplay between ideology and political action in the pursuit of regional integration.

In the context of Latin America, Salvador Rivera offered a comprehensive historical analysis of integration movements. His categorization of its efforts into distinct phases illustrates the resistance faced from entrenched state systems and political classes until the 1990s.³⁸ Rivera’s research highlights the significant role of external powers, particularly the United States, in thwarting unification ambitions, emphasizing that struggles for unity were not confined to the Arab world but were prevalent in other regions as well. As Gian Gardini argues, Latin America has the richest tradition, and perhaps the most sophisticated, of modern unification attempts in comparison to other regions.³⁹

There are many more works on specific case studies that can be reviewed. The literature addressing episodes of supranational unification across different regions reveals a complex interplay of ambition and resistance. While these works contribute valuable insights into the motivations and challenges behind unification, they underscore a recurring theme: the disjunction between ideological aspirations and political realities. This critical examination not only enhances our understanding of past attempts at unification but also sets the stage for identifying gaps in the current scholarship and exploring the potential for future research.

 

Gaps in the Literature and Further Investigation

With a few exceptions, the existing body of research on political unification seems outdated and seldom revisited. Foundational theoretical frameworks remain mostly unchallenged or unutilized. However, this body of literature is considerable enough that it lays down foundations that can be further developed and built upon. Nonetheless, significant gaps remain, particularly when examining contemporary challenges and the evolving political landscape of the Umma today, and more broadly of the Global South. Moreover, there are areas of research that can be investigated related to the scope of this review that can enrich and inform it but lie within the domains of other research questions and framings.

While aspirations to political unification are still persistent, this is not reflected in current research. Frameworks could be revisited and applied, particularly to the ongoing unification attempt of Mali, Burkina Faso, and Niger. Moreover, such frameworks or theories could be more tailored or new ones created that are more suited to the current realities of Muslim polities. There is a need to examine what variables differentiate the Umma and the Global South from Europe regarding the viability of political unification and integration. Existing research tends to apply European models of integration to other regions without fully accounting for unique political, cultural, and historical contexts. Future studies should explore whether factors specific to the Muslim world, such as religious influence, colonial legacies, or tribal affiliations, necessitate a different approach to the study of political unification. Such research could help redirect the study of unification and integration by focusing on the internal dynamics and external pressures that make the Islamic world distinct from Europe, thus paving the way for more comprehensive or context-specific frameworks for unification.

Existing scholarship has focused on historical efforts such as pan-Arabism and Pan-Africanism, yet little attention is given to how current ideologies—such as nationalism, populism, and statism, which tend to be associated with authoritarianism—hinder present-day unification or integration efforts. How these ideologies interact with unifying ideologies such as pan-Arabism or ummatic discourses can be explored. Moreover, investigating how populist and authoritarian leaders manipulate nationalist sentiments to maintain power would be helpful. Focusing on elite dynamics in the light of authoritarianism could enhance the body of literature on existing examined case studies. How all of this affects attempts at regional cooperation could provide deeper insights on the barriers to political unification today.

Investigating the institutional designs and processes of such attempts could provide useful insights as well. In cases of successful political unification, are there patterns or key variables of institutional design that can be identified? How were issues related to economic and financial institutions addressed? How have they hindered or contributed to the success or failure of political unification? What would be the salient distinctions between federal design in unification as opposed to non-unification cases? Further inquiry could be made into the government bureaucracy, judiciary system, and security institutions. Special attention can be given to civil military relations as well in contexts of political unification. All these potential topics of research would prompt more investigation of federalism and different forms of governance including decentralization. Moreover, with regards to civil military relations, what were the roles of militaries in political unification? Does the military have to be professional? Do unification attempts have a correlation with military coups or in any way anticipate them? Are there similarities in the militaries or the transformation of militaries in successful cases of political unification? These are some questions worth exploring.

A central piece of the puzzle for further research could be which countries in the world today, particularly in Muslim countries, are most ripe for political unification or reunification. Perhaps developing an index which quantifies specific variables between various countries can help answer these questions. Such an index based on variables measurable over time can create useful datasets for further research. This can apply to Muslim countries that were unified in various historical periods. Cases like Türkiye and Azerbaijan with their “One Nation Two States” discourse may be relevant.

Another promising area of research concerns the role of localized, non-state entities in contributing to political unification. Current studies often frame unification efforts as top-down processes driven by state actors, yet local communities, civil society, and religious organizations wield considerable influence in shaping regional identities. Investigating how non-state actors, such as tribes, religious movements, and grassroots organizations, contribute to or hinder political unification efforts in the Islamic world could uncover alternative pathways to integration. These actors often operate outside formal state structures, yet they hold significant sway over local populations, making them crucial players in the quest for unification.

Another area of research can extend to investigate exogenous variables associated with political unification. How do other states typically respond to political unification and what patterns can be observed in responsive foreign policies? In cases where political unification arose without an external security threat, do alliances typically form to balance against the newly unified state? How do international organizations react to them: do they facilitate or hinder their success?

In summation, the literature on political unification exhibits gaps that prompt further investigation. While the existing theoretical frameworks provide valuable starting points to the understanding of political unification, they remain underexplored and undercontested. Moreover, they display a Eurocentric bias and tend to overlook the distinct traits of the Global South and the Muslim World. Further research could benefit from focusing on institutions, contemporary ideologies, the roles of non-state actors as well as the reactions of other states and external actors observing unification.

 

Bibliography

Adamolekun, Ladipo. “Introduction: Federalism in Nigeria.” Publius 21, no. 4 (1991): 1–11. http://www.jstor.org/stable/3330307.

Adamolekun, Ladipo, and S. Bamidele Ayo. “The Evolution of the Nigerian Federal Administration System.” Publius: The Journal of Federalism 19, no. 1 (1989): 157–176. https://www.jstor.org/stable/3330570.

Akram, Ejaz. “Muslim Ummah and its Link with Transnational Muslim Politics.” Islamic Studies 46, no. 3 (2007): 381–415. http://www.jstor.org/stable/20839080.

Anderson, George. Federalism: An Introduction. Oxford: Oxford University Press, 2008.

Anderson, Liam. “Ethnofederalism: The Worst Form of Institutional Arrangement…?” International Security 39, no. 1 (2014): 165–204. https://doi.org/10.1162/ISEC_a_00164.

Bednar, Jenna. The Robust Federation: Principles of Design. Cambridge: Cambridge University Press, 2008.

Bizuneh, Yimenu. “Federalism and State Restructuring in Africa: A Comparative Analysis of Origins, Rationales, and Challenges.” Publius: The Journal of Federalism 54, no. 1 (2024): 6–33. https://doi.org/10.1093/publius/pjad015.

Brennan, Louis, and Philomena Murray, eds. Drivers of Integration and Regionalism in Europe and Asia: Comparative Perspectives. New York: Routledge, 2015.

Connolly, S. J. Kingdoms United?: Great Britain and Ireland since 1500: Integration and Diversity. Dublin: Four Courts Press, 1998.

Cronin, Bruce. Community Under Anarchy: Transnational Identity and the Evolution of Cooperation. New York: Columbia University Press, 1999.

Deutsch, Karl W. Political Community at the International Level: Problems of Definition and Measurement. Garden City, NY: Doubleday, 1954.

Deutsch, Karl W., et al. Political Community and the North American Area. Princeton, NJ: Princeton University Press, 1957. http://www.jstor.org/stable/j.ctt183pvds.

Deutsch, Karl W. Political Community and the North American Area. Princeton, NJ: Princeton University Press, 2015.

Dingli, Sophia. “The Politics of (Re) Unification: Lessons from Yemen for Cyprus.” Cyprus Review 24, no. 2 (2012): 29–43. https://cyprusreview.org/index.php/cr/article/view/133.

Dosenrode, Søren. Limits to Regional Integration. New York: Routledge, 2016.

Dullien, Sebastian, and Ignacio Torreblanca. “What Is Political Union?” European Council on Foreign Relations (2012). https://www.files.ethz.ch/isn/173482/ECFR70_POLITICAL_UNION_BRIEF_AW.pdf.

Elazar, Daniel J. “Federalism and Consociational Regimes.” Publius 15, no. 2 (1985): 17–34. http://www.jstor.org/stable/3329962.

Elazar, Daniel J. “Contrasting Unitary and Federal Systems.” International Political Science Review 18, no. 3 (1997): 237–51. http://www.jstor.org/stable/1601342.

Englebert, Pierre, and Rebecca Hummel. “Let’s Stick Together: Understanding Africa’s Secessionist Deficit.” African Affairs 104, no. 416 (2005): 399–427. https://www.jstor.org/stable/3518722.

Erk, Jan, and Lawrence Anderson. “The Paradox of Federalism: Does Self-Rule Accommodate or Exacerbate Ethnic Divisions?” Regional & Federal Studies 19, no. 2 (2009): 191–202. https://doi.org/10.1080/13597560902753388.

Etzioni, Amitai. “The Dialectics of Supranational Unification.” The American Political Science Review 56, no. 4 (1962): 927–35. https://doi.org/10.2307/1952794.

Etzioni, Amitai. “The Epigenesis of Political Communities at the International Level.” American Journal of Sociology 68, no. 4 (1963): 407–21. http://www.jstor.org/stable/2774421.

Etzioni, Amitai. Political Unification Revisited: On Building Supranational Communities. Lanham, MD: Lexington Books, 2001.

Etzioni, Amitai. “A Paradigm for the Study of Political Unification.” In The Structure of Political Geography, 221–30. New York: Routledge, 2011. https://doi.org/10.4324/9781315135267-22.

Figueiredo, Rui J. P. de, and Barry R. Weingast. “Self-Enforcing Federalism.” The Journal of Law, Economics, and Organization 21, no. 1 (2005): 103–35. https://www.jstor.org/stable/3554986.

Filippov, Mikhail, P. C. Ordeshook, and O. Shvetsova. Designing Federalism: A Theory of Self-Sustainable Federal Institutions. Cambridge: Cambridge University Press, 2004.

Gardini, Gian Luca. “Unity and Diversity in Latin American Visions of Regional Integration.” In Latin American Foreign Policies: Between Ideology and Pragmatism, 235–54. New York: Palgrave Macmillan US, 2011.

Griffiths, Ryan D. “Security Threats, Linguistic Homogeneity, and the Necessary Conditions for Political Unification.” Nations and Nationalism 16, no. 1 (2010): 169–88. https://doi.org/10.1111/j.1469-8129.2010.00429.x.

Haas, Ernst B. “International Integration: The European and the Universal Process.” International Organization 15, no. 3 (1961): 366–92. https://doi.org/10.1017/s0020818300002198.

Haas, Ernst B., and Philippe C. Schmitter. “Economics and Differential Patterns of Political Integration: Projections about Unity in Latin America.” International Organization 18, no. 4 (1964): 705–37. https://www.jstor.org/stable/2705528.

Haas, Ernst B. The Uniting of Europe: Political, Social, and Economic Forces, 1950-1957. Notre Dame, Ind: University of Notre Dame Press, 2020.

Hamid, Sadek. “Islam Beyond Borders: Building Ummatic Solidarity in the 21st Century.” Ummatics, November 20, 2023. https://ummatics.org/society-and-civilization/islam-beyond-borders-building-ummatic-solidarity-in-the-21st-century/.

Hale, Henry. “Divided We Stand: Institutional Sources of Ethnofederal State Survival and Collapse.” World Politics 56, no. 2 (2004): 165–93. https://www.jstor.org/stable/25054254.

Hick, Ursula K. Federalism: Failure and Success: A Comparative Study. New York: Oxford University Press, 1979.

Hueglin, Thomas O., and Alan Fenna. Comparative Federalism: A Systematic Inquiry. Toronto: University of Toronto Press, 2015.

Hülsmann, J. G. “Political Unification: A Generalized Progression Theorem.” Journal of Libertarian Studies 13 (1997): 81–96.

Isani, Mujtaba Ali, Daniel Silverman, and Joseph Kaminski. “The Other Legitimate Game in Town? Understanding Public Support for the Caliphate in the Islamic World.” American Journal of Islam and Society 41, no. 2 (August 1, 2024): 80–117. https://doi.org/10.35632/ajis.v41i2.3283.

Kincaid, John. “Values and Value Tradeoffs in Federalism.” Publius 25, no. 2 (1995): 29–44. https://www.jstor.org/stable/3330826.

Lijphart, Arend. “Cultural Diversity and Theories of Political Integration.” Canadian Journal of Political Science 4, no. 1 (March 1971): 1–14.

Martin, Guy. “Dream of Unity: From the United States of Africa to the Federation of African States.” African and Asian Studies 12, no. 3 (2013): 169–88. https://doi.org/10.1163/15692108-12341261.

McGarry, John, and Brendan O’Leary. Federation and Managing Nations. London: Routledge, 2007.

Means, Gordon P. “Eastern Malaysia: The Politics of Federalism.” Asian Survey 8, no. 4 (1968): 289–308. https://doi.org/10.2307/2642203.

Mohamedou, Mohammad-Mahmoud Ould. “The Rise and Fall of Pan-Arabism.” In Routledge Handbook of South-South Relations, 168–76. New York: Routledge, 2018.

Mufti, Malik. Sovereign Creations: Pan-Arabism and Political Order in Syria and Iraq. Ithaca, NY: Cornell University Press, 1996.

Nonneman, Gerd. “The Yemen Republic: From Unification and Liberalization to Civil War and Beyond.” In The Middle East in the New World Order, 61–96. London: Palgrave Macmillan, 1997.

Nye, Joseph S. “Patterns and Catalysts in Regional Integration.” International Organization 19, no. 4 (1965): 870–84. https://www.jstor.org/stable/2705647.

Nye, Joseph S. “Comparative Regional Integration: Concept and Measurement.” International Organization 22, no. 4 (1968): 855–80. https://www.jstor.org/stable/2705847.

Nye, Joseph S. Pan-Africanism and East African Integration. Cambridge, MA: Harvard University Press, 1965.

Pagano, Michael A., ed. The Dynamics of Federalism in National and Supranational Political Systems. New York: Springer, 2007.

Parent, Joseph. Uniting States: Voluntary Union in World Politics. Oxford: Oxford University Press, 2012.

Podeh, Elie. The Decline of Arab Unity: The Rise and Fall of the United Arab Republic. Liverpool: Liverpool University Press, 2015.

Rivera, S. Latin American Unification: A History of Political and Economic Integration Efforts. Jefferson, NC: McFarland, 2014.

Riker, William H. Federalism: Origin, Operation, Significance. Boston: Little, Brown, 1964.

Riker, William H. The Development of American Federalism. Boston: Kluwer Academic Publishers, 1987.

Scharpf, Fritz W. “The Joint‐Decision Trap: Lessons from German Federalism and European Integration.” Public Administration 66, no. 3 (1988): 239–78. https://doi.org/10.1111/j.1467-9299.1988.tb00694.x.

Simeon, Richard, and Barry A. Radin. “Reflections on Comparing Federalisms: Canada and the United States.” Publius: The Journal of Federalism 40, no. 3 (2010): 357–65. https://doi.org/10.1093/publius/pjq008.

Weaver, Ole. “Identity, Integration and Security: Solving the Sovereignty Puzzle in E.U. Studies.” Journal of International Affairs 48, no. 2 (1995): 389–431. http://www.jstor.org/stable/24357597.

 

1. Mohamedou Mohammad-Mahmoud Ould, “The Rise and Fall of Pan-Arabism,” in Routledge Handbook of South-South Relations (London: Routledge, 2018).
2. Nima Khorrami Assl, “The Kingdoms United?” Sada (Carnegie Endowment for International Peace), May 22, 2012, https://carnegieendowment.org/sada/2012/05/the-kingdoms-united.
3. Ryan D. Griffiths, “Security Threats, Linguistic Homogeneity, and the Necessary Conditions for Political Unification,” Nations and Nationalism 16, no. 1 (Dec 2009): 169–88.
4. See Mujtaba Ali Isani, Daniel Silverman, and Joseph Kaminski. “The Other Legitimate Game in Town? Understanding Public Support for the Caliphate in the Islamic World,” American Journal of Islam and Society 41, no. 2 (August 1, 2024): 80–117; Sadek Hamid, “Islam Beyond Borders: Building Ummatic Solidarity in the 21st Century,” Ummatics, November 20, 2023, https://ummatics.org/society-and-civilization/islam-beyond-borders-building-ummatic-solidarity-in-the-21st-century/; and Ejaz Akram, “Muslim Ummah and its Link with Transnational Muslim Politics,” Islamic Studies 46, no. 3 (2007): 381–415.
5. The label “supranational” is nowadays more associated with governance of institutes that govern collective policies of European Union member countries.
6. Ole Weaver, “Identity, Integration and Security: Solving the Sovereignty Puzzle in E.U. Studies,” Journal of International Affairs 48, no. 2 (1995): 389–431.
7. Amitai Etzioni, Political Unification Revisited on Building Supranational Communities (Lexington: Lexington Books, 2002), xxv.
8. Ernst B. Haas, The Uniting of Europe: Political, Social, and Economic Forces, 1950-1957 (Notre Dame, Ind: University of Notre Dame Press, 2020 [1958]).
9. Ernst B. Haas, “International Integration: The European and the Universal Process,” International Organization 15, no. 3 (1961): 366–392.
10. Ernst B. Haas and Philippe C. Schmitter. “Economics and Differential Patterns of Political Integration: Projections about Unity in Latin America,” International Organization 18, no. 4 (1964): 705–737.
11. Søren Dosenrode, Limits to Regional Integration (London: Routledge, 2016).
12. Joseph S. Nye, “Patterns and Catalysts in Regional Integration,” International Organization 19, no. 4 (1965): 870–884.
13. Karl Deutsch, Political Community at the International Level; Problems of Definition and Measurement (Garden City, N.Y: Archon Books, 1970).
14. Karl Deutsch, Political Community and the North American Area (Princeton: Princeton University Press, 2015).
15. Amitai Etzioni, Political Unification Revisited. This book elaborates and builds on an older article, Amitai Etzioni, “The Dialectics of Supranational Unification,” American Political Science Review 56, no. 4 (December 1962): 927–35.
16. Amitai Etzioni, “A Paradigm for the Study of Political Unification,” in The Structure of Political Geography, eds. Julian Minghi and Roger Kasperson (New York: Routledge, 2011), 221–230.
17. Bruce Cronin, Community under Anarchy: Transnational Identity and the Evolution of Cooperation (New York: Columbia University Press, 1999).
18. William H. Riker, Federalism: Origin, Operation, Significance (Boston: Little, Brown, 1964).
19. William H. Riker, The Development of American Federalism (Dordrecht: Springer Netherlands, 1987).
20. Arend Lijphart, “Cultural Diversity and Theories of Political Integration,” Canadian Journal of Political Science 4, no. 1 (March 1971): 1–14.
21. Ryan D. Griffiths, “Security Threats, Linguistic Homogeneity, and the Necessary Conditions for Political Unification,” Nations and Nationalism 16, no. 1 (Dec 2009): 169–88.
22. Joseph M. Parent, Uniting States: Voluntary Union in World Politics (Oxford: Oxford University Press, 2011).
23. Ernst Haas, “International Integration.”
24. Karl Deutsch, Political Community at the International Level.
25. Etzioni, Political Unification Revisited.
26. Jenna Bednar, The Robust Federation: Principles of Design (Cambridge: Cambridge University Press, 2009).
27. William Riker and Jonathan Lemco, “The Relation between Structure and Stability in Federal Governments,” in The Development of American Federalism, ed. William Riker (Boston: Kluwer Academic Publishers, 1987), 113-129.
28. Jan Erk and Lawrence Anderson, “The Paradox of Federalism: Does Self-Rule Accommodate or Exacerbate Ethnic Divisions?” Regional & Federal Studies 19, no. 2 (May 2009): 191–202.
29. Liam Anderson, “Ethnofederalism: The Worst Form of Institutional Arrangement…?” International Security 39, no. 1 (July 2014): 165–204.
30. Mikhail Filippov, Peter C. Ordeshook, and Olga Shvetsova, Designing Federalism: A Theory of Self-Sustainable Federal Institutions (New York: Cambridge University Press, 2004).
31. John McGarry and Brendan O’Leary, Federation and Managing Nations (London: Routledge, 2007).
32. R. J. de Figueiredo, and Barry R Weingast “Self-Enforcing Federalism,” Journal of Law, Economics, and Organization 21, no. 1 (April 2005): 103–35.
33. Malik Mufti, Sovereign Creations: Pan-Arabism and Political Order in Syria and Iraq (Ithaca, NY: Cornell University Press, 2019).
34. Elie Podeh, The Decline of Arab Unity: The Rise and Fall of the United Arab Republic (Liverpool: Liverpool University Press, 2015).
35. Gerd Nonneman, “The Yemen Republic: From Unification and Liberalization to Civil War and Beyond,” in The Middle East in the New World Order, ed. Haifaa A. Jawad (London: Palgrave Macmillan, 1997), 61–96.
36. Guy Martin, “Dream of Unity: From the United States of Africa to the Federation of African States,” African and Asian Studies 12, no. 3 (2013): 169–88.
37. Joseph S. Nye, Pan-Africanism and East African Integration (Cambridge, Mass: Harvard University Press, 1966).
38. Salvador Rivera, Latin American Unification: A History of Political and Economic Integration Efforts (Jefferson, NC: McFarland, 2014).
39. Gian Luca Gardini, “Unity and Diversity in Latin American Visions of Regional Integration,” in Latin American Foreign Policies: Between Ideology and Pragmatism, eds. Gian Luca Gardini and Peter Lambert (New York: Palgrave Macmillan, 2011), 235-254.