IN his science fiction masterpiece The Three-Body Problem, Liu Cixin depicts a civilization trapped in a system besieged by the unforgiving interactions of three suns—its progress condemned to recurring catastrophes caused by celestial disorder.
THAT metaphor resonates powerfully today. As the international system moves away from the imperfect but steady orbit of the Pax Americana, it has entered a far less predictable configuration. The interaction between the incumbent power and resurgent and rising challengers has produced a geopolitical “many-body problem,” raising a fundamental question: can Pax Multipolaris exist—in other words, can a multipolar balance bring lasting peace?
THIS issue of Horizons begins with a basic premise: the post–Cold War order is over, but no coherent replacement has yet emerged. The present moment is defined less by transition than by accumulation—unresolved conflicts, overlapping power centers, and institutions designed for a world that no longer exists. The result is not equilibrium, but mounting friction.
ACROSS our pages, contributors converge on a central observation: power is dispersing faster than the rules that once constrained and channeled it. Institutions intended to manage rivalry now struggle to enforce norms consistently or to mediate crises among increasingly self-confident actors. In response, diplomacy has become more situational and transactional, relying on improvised mechanisms rather than durable frameworks. Order has not disappeared, but it has weakened immensely.
MEANWHILE, the emerging landscape cannot be reduced to great-power rivalry alone. For many states, particularly outside the main centers of gravity, multipolarity has expanded strategic options. Regional actors and middle powers are asserting autonomy, recalibrating partnerships, and resisting fixed alignment. This diffusion of agency complicates inherited models of hierarchy and challenges assumptions about who shapes the international system.
THE unresolved question is whether restraint can keep pace with the widening distribution of power. Historically, multipolar systems have endured only when competition was bounded by credible limits and shared expectations among major actors. Such systems depended on mutual recognition of red lines and a willingness to absorb short-term costs to avoid systemic breakdown. Where those habits were absent, rivalry escalated unchecked.
CRUCIALLY, those stabilizing habits are now under strain in the day-to-day conduct of international politics. Economic interdependence has shifted from reassurance to leverage. Technologies that once promised efficiency now compress decision-making timelines and magnify the risk of miscalculation. As trade, finance, and innovation are increasingly weaponized, the margin for error narrows. Managing competition—rather than imagining its resolution—has become the central task of statecraft.
ULTIMATELY, the “many-body problem” has no general solution. Whether Pax Multipolaris emerges as a viable order or dissolves into systemic turbulence hinges on three pivotal choices: the depth of diplomatic engagement, the restoration of institutional legitimacy, and the willingness to accept limits in the exercise of power. Those choices, more than any others, will shape the geopolitical landscape of the years ahead.
