An emergency United Nations Security Council meeting dissolved into bitter recriminations between the United States, Israel, and Iran on Saturday, with Secretary-General António Guterres condemning all sides' military actions in a stark display of the institution's powerlessness to contain the escalating Middle East crisis.The session, convened at Tehran's request following joint US-Israeli strikes that reportedly killed Supreme Leader Ayatollah Ali Khamenei, showcased the diplomatic paralysis that grips the UN's highest body when permanent Security Council members are direct parties to conflict.Guterres urged all parties to exercise restraint and return to dialogue, warning that the conflict risks spiraling into a regional conflagration that could draw in multiple nations and destabilize the global economy. His calls went unheeded as American, Israeli, and Iranian representatives exchanged accusations in language that barely maintained diplomatic veneer.To understand today's headlines, we must look at yesterday's decisions. The Security Council's inability to address conflicts involving permanent members is not a bug but a feature—the veto power held by the US, Russia, China, France, and Britain was designed to prevent the UN from taking action against great powers, precisely to avoid the institutional collapse that doomed the League of Nations.But that structural reality means the Council becomes a theater for performative denunciations rather than substantive diplomacy when major powers clash. Russia and China have criticized American military action against Iran, though neither has moved beyond rhetoric to material support for Tehran. Western diplomats suspect both nations are content to see Washington bogged down in Middle Eastern conflict.Iranian Ambassador Amir Saeid Iravani delivered a blistering address condemning what he characterized as "state terrorism" and "assassination of national leaders." He demanded the Council take action against Washington and Jerusalem, knowing full well the American veto makes such action impossible.US Ambassador Linda Thomas-Greenfield defended American actions as justified self-defense against Iranian aggression, citing years of attacks on American personnel and interests across the Middle East. She accused Tehran of sponsoring terrorism and seeking nuclear weapons, charges Iranian officials vehemently deny.Israeli representatives echoed American justifications, with Ambassador Danny Danon asserting that Iran's leadership constituted an existential threat to Israel that justified preemptive action.The session's futility underscores deeper questions about multilateral diplomacy's relevance in an era of renewed great power competition. The institutions built after World War II presumed American hegemony and basic agreement among major powers on international norms. Neither presumption holds in 2026.Guterres has increasingly spoken out about the Council's dysfunction, warning that without reform, the UN risks irrelevance. But reform requires agreement among the very powers whose conflicts paralyze the institution—a circular problem with no obvious solution.Smaller nations on the Council, watching the great powers clash, face their own dilemma. Supporting either side risks antagonizing the other, but silence suggests complicity in the Council's failure. Most have opted for generic calls for de-escalation that satisfy neither camp but avoid direct confrontation.The broader implication is that multilateral diplomacy has limits when fundamental interests of major powers collide. The Council can address conflicts in peripheral regions where great powers agree, but becomes impotent precisely when its authority is most needed—in conflicts among the powerful themselves.As the Iran crisis escalates, the world is being reminded that international law and institutions function only when major powers choose to be constrained by them. When they do not, the carefully constructed architecture of global governance becomes mere decoration on a system still fundamentally governed by power.