Spheres of Security: Balancing Great Power Interests and Global Stability

Spheres of Security: Balancing Great Power Interests and Global StabilityExecutive SummaryThis briefing document synthesizes the dialogue between Professor Jeffrey Sachs and Professor John Mearsheimer regarding the proposed concept of "spheres of security." The central debate explores whether great powers can avoid existential conflict—specifically nuclear war—by mutually respecting defined regional "neighborhoods."While both experts agree that the expansion of NATO into Ukraine and Georgia was a catastrophic strategic error that ignored Russia’s legitimate security concerns, they diverge on the viability of formalizing "spheres of security." Jeffrey Sachs proposes these spheres as a "positive-sum" mechanism for cooperation, modeled on self-imposed restraint and mutual non-interference. Conversely, John Mearsheimer argues from a realist perspective, asserting that the "tragedy" of great power politics makes such arrangements inherently unstable due to the "security dilemma," the uncertainty of state intentions, and the competitive nature of relative power gains.