Vladimir Putin was not going to miss his chance to use winter as a weapon. In recent weeks, Russian missile strikes have hammered the power grid and neighborhood heating systems, leaving both on the verge of collapse. Last week, President Trump appealed to Putin to pause these attacks for a week, long enough for the cold snap to pass and peace talks to move forward. Putin initially appeared to acquiesce—then launched one of the worst attacks on Ukraine’s energy network since the start of the war.