 Donald Trump is no fan of NATO. He said the alliance is a raw deal for the United States and a sweet deal for some freeloading members that fail to contribute as much to their own defense as the rules require. Actually, plenty of other U.S. presidents have complained about this same thing. But Trump was the first, as president, to threaten to pull the U.S. out of the alliance unless European countries pay up. And now those countries are confronting the fear that if he is reelected, Donald Trump might make good on that threat.