Major Foreign Policy Themes (cont) The Era of Internationalism began with bombing of pearl Harbor and U.S entry into World War II resulted in significant increases in defense spending emerged from World War II with a strengthened econom controlled nuclear weaponsMajor Foreign Policy Themes (cont.) The Era of Internationalism began with bombing of Pearl Harbor, and U.S. entry into World War II resulted in significant increases in defense spending emerged from World War II with a strengthened economy controlled nuclear weapons