Germany annexed Austria in 1938, and soon turned its attention to its eastern neighbors. Roosevelt made it clear that, in the event of German aggression against Czechoslovakia, the U.S. would remain neutral. After completion of the Munich Agreement and the execution of Kristallnacht, American public opinion turned against Germany, and Roosevelt began preparing for a possible war with Germany. Relying on an interventionist political coalition of Southern Democrats and business-oriented Republicans, Roosevelt oversaw the expansion of U.S. airpower and war production capacity.