Along NATO's eastern edge, the presidents of Lithuania and Latvia have raised a formal alarm: Russia is planning deliberate strikes against the power grids and rail networks that sustain life in the Baltic states and Poland. The warning, grounded in intelligence traced to Moscow's highest offices, arrives as the war in Ukraine surpasses four years with no resolution in sight. What is at stake is not merely infrastructure, but the credibility of collective defense — whether an alliance built on mutual guarantees will hold when tested by acts that blur the boundary between sabotage and war.