• The weakening of multilateralism should therefore be understood as a central driver of global instability, not a secondary consequence. As established frameworks are sidelined and power fills the resulting gaps, predictability fades and competition hardens
  
• The author is a political scientist with a Ph.D. in Political Science and International Relations at the University of Vienna.

ISTANBUL

The root of today’s global instability lies not in the sheer number or pace of crises, but in the steady unraveling of the multilateral regimes meant to govern them. As major powers increasingly operate through parallel structures, particularly in the Middle East, regional rivalries have become more rigid, more enduring, and more difficult to de-escalate. The United States’ growing reliance on ad hoc arrangements outside established multilateral frameworks has been especially consequential, reinforcing dynamics that privilege coercion and uncertainty over predictability and rule-based restraint.

The international system is thus not only facing a proliferation of crises, but also a steady weakening of the rules and institutions expected to regulate them. Conflicts in the Middle East, tensions over energy corridors, the re-securitization of nuclear issues, and the intensification of great power rivalry all point to a deeper structural transformation: the erosion of multilateralism and the declining effectiveness of international regimes.

Many of today’s global challenges are therefore better understood not as the outcome of isolated policy choices by individual states, but as the result of the gradual disintegration of the normative and institutional architecture underpinning the international order.

Power politics gain strength as rules-based order weakens

In the post-Cold War era, international politics was largely shaped by the ambition to construct a rules-based order. International regimes in areas such as energy security, nuclear non-proliferation, trade, and collective security were designed to generate predictability through shared principles, norms, rules, and decision-making procedures. These regimes did not eliminate conflict, but they provided structured channels for managing competition and mitigating escalation.

In recent years, however, foreign policy practices – most visibly those led by the US – have increasingly undermined the binding force of these regimes. The unilateralist turn that gained momentum during the US President Donald Trump administration, characterized by the questioning of multilateral agreements, the bypassing of institutional mechanisms, and the prioritization of bilateral bargaining, marked a decisive shift. The consequences extended beyond the withdrawal from specific agreements; they eroded the normative legitimacy of regimes themselves.

This retreat from rules has facilitated the return of power politics. As regimes lose credibility and enforcement capacity, strategic interaction becomes more transactional, less predictable, and more heavily reliant on coercive instruments. The weakening of multilateralism thus does not simply coexist with power politics; it actively enables its resurgence.

Retreat from multilateralism or search for a new order?

The US’ distancing from multilateralism cannot be reduced to a desire to avoid institutional constraints. Washington has increasingly pursued policies through parallel decision-making and implementation channels that effectively bypass existing regimes. While this trend became more pronounced under the Trump administration, it has persisted in modified forms thereafter.

The core motivation behind these parallel structures is the maximization of strategic flexibility. Multilateral processes are often perceived as slow, constraining, and politically costly. In response, alternative arrangements have emerged: narrow coercive tools replacing broad-based nuclear oversight, bilateral trade deals supplanting multilateral trade regimes, and temporary security coalitions substituting for collective decision-making mechanisms.

Crucially, these parallel structures do not seek to dismantle existing regimes outright. Instead, they render them functionally obsolete. Regimes remain formally intact, but substantive decisions are increasingly made elsewhere. The result is an international order in which institutions persist on paper while power is exercised through informal, selective, and often opaque channels.

The Iran case: Where parallel governance politics crystallize

The US-Iran confrontation represents one of the clearest cases in which parallel governance politics have effectively sidelined multilateral regimes. The US’ unilateral withdrawal from the Joint Comprehensive Plan of Action (JCPOA) in 2018 not only disrupted Iran’s nuclear program but also undermined the shared expectations and trust framework upon which the agreement was built. What followed was not the establishment of a new multilateral regime, but rather a parallel implementation order based on sanctions, bilateral pressure mechanisms, and limited coordination.

While this approach may offer short-term flexibility and coercive leverage, it significantly weakens the long-term restorative capacity of international regimes. The JCPOA was not merely a technical non-proliferation arrangement; it was a confidence-building structure embedded in a broader regime logic. Its abandonment signaled that even highly institutionalized agreements could be reversed unilaterally, thereby reducing incentives for compliance and cooperation.

Iran’s responses should therefore not be interpreted solely through the lens of immediate security concerns. They also constitute systemic reactions to the loss of predictability in the international order. As regime-based assurances eroded, strategic ambiguity and incremental escalation became rational instruments of adaptation.

The Iran file cannot be reduced to a bilateral dispute between Washington and Tehran. It is embedded in a broader triangular dynamic involving Israel’s regional security perceptions and strategic priorities. From Israel’s perspective, Iran represents not merely a state approaching nuclear capability, but a structural challenger capable of altering regional power balances.

Keeping Iran outside the system both reinforces Israel’s regional position and preserves US freedom of maneuver. The cost, however, is borne by the international order itself: the erosion of regimes and the weakening of shared normative foundations.

The precondition for stability: regime functionality

International organizations and agreements serve as the structural carriers of regimes, yet they cannot generate stability on their own. Their effectiveness depends on trust in decision-making processes, the credibility of implementation, and the certainty that violations will not go unanswered. When these conditions erode, regimes may persist formally while losing their capacity to manage crises.

The effective functioning of regimes depends on the ability of relevant actors to come together around shared principles with strong political will, to develop rules that translate these principles into patterns of behavior, and to apply sound and credible decision-making processes. It also requires all relevant actors to engage in the process with sustained commitment.

Multilateral regime instruments – monitoring, transparency, coordination, and crisis management – are therefore not merely technical tools. They are the system’s mechanisms of self-repair. When they are selectively applied or systematically bypassed, uncertainty deepens and power politics inevitably reasserts itself.

Conclusion

In recent years, the choices made by major powers and regional actors alike have reinforced the erosion of multilateralism. As states increasingly prioritize unilateral flexibility over collective responsibility, parallel arrangements replace common frameworks and short-term calculations overshadow long-term stability. This shift does not remain confined to one region or one set of actors. It shapes how countries respond to security threats, energy competition, and strategic rivalry across the system.

The weakening of multilateralism should therefore be understood as a central driver of global instability, not a secondary consequence. As established frameworks are sidelined and power fills the resulting gaps, predictability fades and competition hardens. Under these conditions, the return of power politics is not a sudden rupture, but the foreseeable outcome of an international order that has lost its stabilizing foundations.

*Opinions expressed in this article are the author's own and do not necessarily reflect the editorial policy of Anadolu.