The fight against Russia in Ukraine is now firmly Europe’s war. The European Union this week signed off on the equivalent of $105 billion in loans to keep Kyiv afloat through the end of next year—but officials warned that it may not be enough. With Russia determined to continue its four-year invasion until it dominates its neighbor, and President Trump pulling back from Europe and focused on the Middle East, Ukraine finds itself reliant on the traditionally gun-shy EU in its war for survival. The confirmation of the loan ahead of a summit in Cyprus on Thursday, long blocked by...