If Donald Trump wins a second term in the White House in November, NATO may fall apart, a recent wargame found. As a presidential candidate, Trump has threatened to quit NATO unless European allies contribute more, and should he carry it out Europe may decide to go it alone on defense, the game suggests. "A US policy of frustrating NATO has the potential to cause the alliance to collapse, with the EU as a candidate for eventually replacing NATO's ultimate function — defending Europe from Russia," wrote Finley Grimble, the British defense expert who designed and ran the game. The...