The euro crisis seems to vindicate her skepticism, and with serendipitous timing, she's on the big screen in a biopic, played by Meryl Streep. A British Prime Minister, splendidly isolated, faces down a phalanx of scowling European leaders, all harrumphing censure in accents that are German, French, Italian. We've witnessed the scene before. Decades ago Margaret Thatcher warred with her European counterparts just as David Cameron did this month in refusing to yield control of national budgets to Brussels. The difference is that the Iron Lady did not speak softly when she wielded a big stick. She lambasted ambitious bureaucrats;...