Regional Security Complexes – Americas 2024-2025

Regional Security Complexes – Americas 2024-2025

by Lazar Šljukić and Ana Jovanović

Introduction

The Western Hemisphere cannot be reduced to a single “Pan-American” region. Instead, the Americas are best approached as a set of distinct but interconnected regional security complexes shaped by clustered security interdependence, amity–enmity patterns, and external penetration (Buzan & Wæver 2003). This article applies RSCT to identify three analytically separate complexes: North America, South America, and Central America, and traces how their internal dynamics have evolved in 2024–2025. It argues that the structural map of the hemisphere remains largely stable, while the securitisation agenda increasingly reflects non-traditional threats, institutional fragmentation, and rising penetration, particularly through U.S. coercive involvement both within the hemisphere and across regions.

Applying RSCT to the Region

The Americas do not constitute a single, unified regional security complex. From the perspective of Regional Security Complex Theory (RSCT), the hemisphere is better understood as a set of distinct but interconnected security formations, structured by patterns of geographically clustered security interdependence (Buzan & Wæver 2003).
The main reason a single “Pan-American” complex does not emerge is that security interaction in the Western Hemisphere is not evenly distributed: instead, it forms three analytically separate complexes: North America, South America, and Central America, each shaped by different trajectories of state formation, different amity–enmity patterns, and different degrees of external penetration (Buzan & Wæver 2003).

North America represents the clearest case of a centred regional security complex. In RSCT terms, centred complexes are those in which security dynamics are structured around a dominant actor that functions as the core of the region (Buzan & Wæver 2003).
North America fits this classification because regional security interaction is overwhelmingly organised around the United States, while Canada and Mexico do not operate as autonomous poles but rather as integrated peripheral actors (Buzan & Wæver 2003).
A key structural factor is the early consolidation of the North American state system compared to other regions: independence and state-building occurred well before twentieth-century decolonisation waves, which reduced the intensity of contested borders and allowed institutions to develop earlier and more effectively (Buzan & Wæver 2003).

This historical trajectory contributed to a stable complex largely insulated from traditional interstate military rivalry. Amity patterns are also central. Relations between the United States and Canada represent one of the strongest cases of institutionalised amity, while U.S.–Mexico relations, though asymmetrical and periodically tense, remain largely framed through interdependence rather than existential enmity. This configuration produces a regional structure in which security issues are managed within a stable hierarchy rather than through balancing or rivalry, reinforcing North America’s centred character (Buzan & Wæver 2003).

South America, by contrast, is best classified as a standard regional security complex. Standard complexes are those where security dynamics are regionally autonomous but decentralised, without a single uncontested centre (Buzan & Wæver 2003). South America’s formation was shaped by early nineteenth-century decolonisation that produced fragmented borders and long-lasting territorial sensitivities. (Bragatti & Weiffen 2023).

These historical conditions created strong enmity patterns and rivalries that affected the development of the complex and left behind strategic “buffer zones” that remain important reference points in regional security perceptions. Over time, however, the region experienced substantial desecuritization of interstate military threats, particularly through democratisation and expanding economic interdependence (Bragatti & Weiffen 2023). In RSCT terms, this did not dissolve the complex; instead, it transformed it into a stable standard complex (Buzan & Wæver 2003). Importantly, South America also exhibits internal differentiation in the form of subcomplexes. The region is commonly divided into the Southern Cone, where patterns of amity and desecuritization are stronger, and the Andean zone, where enmity and internal spillovers have historically been more pronounced. (Bragatti & Weiffen 2023). This subcomplex structure reinforces the classification of South America as a standard complex: cohesive enough to produce region-wide security interdependence, but not centralized enough to generate a single regional core (Buzan & Wæver 2003).

A major theoretical question concerns whether South America could be shifting toward a centred model with Brazil as its core. While Brazil possesses the material capabilities and has periodically pursued regional leadership projects, the RSCT distinction between standard and centred complexes requires not only relative power but also the consolidation of a stable and uncontested centre (Buzan & Wæver 2003). The evidence supports the view that Brazil has not fully achieved this: leadership has been pursued through consensual and cooperative strategies rather than through hegemonic consolidation, and institutional projects remained too fragile to create a durable regional core (Villa 2017; Bragatti & Weiffen 2023). Therefore, South America continues to fit the standard model in Buzan and Wæver’s typology (Buzan & Wæver 2003).

Central America represents the most theoretically ambiguous case in the hemisphere. RSCT offers two competing conceptual lenses: proto-complex and sub-complex. A proto-complex describes a regional cluster where insecurity is clearly interconnected but lacks autonomy and institutional maturity to qualify as a fully developed RSC. A sub-complex, in contrast, refers to a local security cluster whose dynamics are nested inside a larger complex and shaped by penetration from an external actor. Central America displays features of both categories. Its security problems generate strong internal and cross-border interdependence, but the region lacks the institutional depth and autonomy typically required for a fully formed complex. At the same time, Central America is highly penetrated by external powers, especially through frameworks and policies anchored in North America, making it difficult to treat the region as fully autonomous (Buzan & Wæver 2003).

Regional Security Dynamics in 2024-2025

North America in 2024–2025 still behaves like a centred regional security complex, where security dynamics are structured around the United States and its bilateral relationships with Canada and Mexico rather than through a multipolar regional balance. What changes in 2024–2025 is not the polarity of the complex, but the sectoral profile of securitisation. New issues such as continental defence, critical infrastructure, cyber resilience, and transnational public-safety threats are more prominent in official strategies and institutional cooperation than.

The USA–Canada relationship exemplified the highest stage of regional integration: a pluralistic security community where war was unthinkable, and disputes were managed institutionally. That fundamental condition still holds in 2025, but the security agenda has expanded. Issues such as Arctic defence, NORAD modernisation, cyber resilience, and energy transition now dominate the regional discourse. Both countries have invested heavily in early-warning and missile-defence modernisation under the NORAD Renewal and Arctic Defence Initiatives (Government of Canada, 2023; U.S. Department of Defense, 2024) to address emerging threats from Russia and China, while also coordinating on environmental security, wildfire management, and critical mineral supply chains (White House, 2023). Thus, while the core structure of trust and cooperation remains unchanged, the content of their security interaction has shifted toward technological, environmental, and strategic adaptation to global pressures.

The U.S.–Mexico security relationship in 2024–2025 is defined less by classic state-to-state threats and more by high-intensity transnational securitizations such as fentanyl, trafficking networks, migration etc. (CRS, 2025). Trump’s return in January 2025 marks a shift toward coercive border policy and pressure-based cooperation, visible in the administration’s “Securing Our Borders” executive action and the renewed centrality of MPP-style logic (White House, 2025). At the same time, bilateral mechanisms such as the Bicentennial Framework continue to function as stabilisers that keep the relationship within institutionalised cooperation rather than open confrontation (CRS, 2025; U.S. Department of State 2025).

South America has by now abandoned the idea of region-wide security cooperation and entered something that could be best described as fragmented coexistence, where states remain mutually interdependent but lack collective mechanisms for security coordination (Bragatti & Weiffen 2023).

The COVID-19 crisis represents a key starting point for understanding South America’s contemporary security dynamics. It did not create regional insecurity, but it functioned as a stress test that exposed how far regional institutional cooperation had deteriorated (Deciancio & Quiliconi, 2023). UNASUR, while politically fragile, had previously developed ideas for region-wide cooperation, including in the public health sphere. However, by the time COVID hit, UNASUR had effectively ceased functioning, while newer platforms such as PROSUR lacked the legitimacy and institutional capacity to coordinate meaningful collective responses, pushing South America further toward bilateralism and ad hoc coordination rather than durable institutional frameworks (Sanahuja & Verdes-Montenegro, 2021; Nolte, 2022; Bragatti & Weiffen 2023).

At the same time, domestic instability increasingly became the primary destabiliser of the regional security complex, as illustrated by Venezuela’s crisis producing migration spillovers and Colombia’s criminal networks spilling across borders, reinforcing the regional interdependence of insecurity without providing the institutional tools to govern it collectively.

In early January 2026, Venezuela became the scene of a major escalation that also illustrates renewed extra-regional penetration: the United States carried out a dramatic overnight military operation that captured Venezuela’s President Nicolás Maduro, with President Donald Trump publicly claiming the United States would “run” Venezuela until a “safe” transition could be arranged (Reuters, 2026). The intervention was followed by U.S. executive actions aimed at controlling and protecting Venezuelan oil revenues held in U.S. accounts and by high-level discussions with major oil executives regarding investments in Venezuela’s oil sector, signalling that penetration extended beyond coercive action into the sphere of economic governance. (Reuters 2026).

International and Global Dynamics

A key interregional feature of the Americas is that the United States is not merely the central actor within the North American security complex, but also the only global power located inside the broader Americas region (Buzan & Wæver 2003). This gives the Americas a structurally asymmetrical interregional role: a regionally embedded actor becomes a primary source of penetration into other regional security complexes, rather than being primarily shaped by outside influence.

The global influence of the United States is most visible in the Middle East regional security complex, where U.S. military presence and alliance commitments remain among the strongest structuring forces in regional security dynamics. The U.S. maintains a large and geographically dispersed military footprint across the region, with forces stationed in more than a dozen countries and in surrounding waters; CFR notes that this presence expanded in 2024 in response to threats from Iran and Iran-aligned armed groups (CFR, 2024). Reuters reporting similarly describes the architecture of U.S. basing, highlighting Al Udeid Air Base in Qatar (CENTCOM’s forward headquarters) as the largest U.S. base in the region, with roughly 10,000 troops (Reuters 2025). In 2025, this high presence translated directly into coercive interregional intervention: U.S. military activity included strikes linked to the wider Iran–Israel escalation, demonstrating that North America’s centred complex interacts with the Middle East complex not only through diplomacy, but also through sustained force projection (Reuters, 2025).

South America has maintained a relatively high degree of autonomy from external powers compared to other regions, but this autonomy is constrained by weak regional institutions. Relations with North America and other global actors are largely bilateral rather than institutionalized at the regional level. The COVID-19 pandemic exposed these limitations, as the absence of effective regional mechanisms forced South American states to rely on ad hoc national responses and bilateral cooperation with external partners. This confirmed the region’s peripheral position in global security governance.

Central America is the most externally penetrated region in the hemisphere. U.S. security initiatives, migration policies, and cooperation with Mexico effectively integrate Central America into North American security strategies. While this penetration limits regional autonomy, it does not eliminate internally generated security interdependence, reinforcing Central America’s ambiguous classification within RSCT.

Continuities, Changes, and Future Outlook

Despite several visible shifts, the Americas’ core security patterns remain consistent with the RSCT logic outlined in Regions and Powers. The hemisphere is still best understood as three distinct but interconnected regional security complexes: North America, South America, and Central America, whose fundamental structures are unlikely to change in the near future. North America will remain a centred complex dominated by the United States, while South America will likely continue to function as a standard complex characterised by fragmented coordination and the absence of a stable regional core.

At the same time, the last few years have introduced transformations that reshape the region’s security agenda without altering its structural map. Trump’s return to the presidency in January 2025 has further strengthened the probability of coercive and intervention-oriented penetration dynamics, both through hard border securitisation and through force projection beyond the region, particularly in the Middle East. Looking forward, the main trend is therefore not structural change, but increasing complexity: regional security will be shaped less by classic interstate rivalry and more by the interaction between domestic spillovers, weak institutional coordination, and escalating penetration from external powers, patterns that will likely deepen rather than fade in the years ahead

Conclusion

Looking towards 2030, we expect the Americas’ regional security architecture to remain broadly stable in structural terms: North America will continue to function as a centred complex, while South America is unlikely to consolidate into a centred order and will instead remain fragmented, with weak regional coordination mechanisms. Rather than structural transformation, the most probable trajectory is the continuation and deepening of recent trends such as widening securitisation agendas, persistent domestic spillovers, and intensified penetration dynamics. Under these conditions, security outcomes will increasingly be shaped by the interaction between transnational flows (migration, illicit networks), institutional capacity, and coercive external influence. In particular, a more intervention-oriented U.S. posture after 2025 suggests that interregional dynamics will play a growing role in shaping hemispheric security, especially through crisis escalation and pressure-based governance.

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