This article contends that separation of powers offers a mitigating force in answering questions about the limits of the authority of the UN’s primary organs and provides a tool through which one can identify where the rule of law is under threat. Whether or not one agrees that separation of powers as such has legal applicability to the UN in a strict sense, there is value in casting the separation of powers lens over the organization as it operates now. This exercise is worthwhile not just for posterity but also because evolution of law ought to be carefully monitored, particularly at a time when regard for the fundamental norms of international law are subject to increasing derision and even direct challenge. That contemporary political tensions have slowed the Security Council from its earlier activism is precisely why this article is timely, because it is in these times that institutional memory gets lost, the boundaries of authority blur, and populist narratives bring the rule of law under threat.