At the margins of the United Nations General Assembly, Poland's Foreign Minister Radoslaw Sikorski offered a measured but consequential judgment: Russia, ground down by its war in Ukraine, no longer possesses the military capacity to invade NATO. The words carry particular gravity from a diplomat whose nation stands on the alliance's eastern edge, shaped by centuries of knowing what it means to live in the shadow of larger powers. In naming a limit to Russian strength, Sikorski drew a line not only around a military assessment, but around the meaning of deterrence itself — the idea that allian