If President Donald Trump is serious about pulling out of NATO, he would begin first by pulling U.S. troops out of Europe, particularly Germany. He could use an exit line from Groucho Marx who used to say, “I wouldn’t want to be in any club that would have me as a member.” The problem for Europe is that without the U.S., there would be no NATO. The U.S founded NATO after World War II to protect Europe from Russia, then the Soviet Union, and has been supporting it ever since. Back then, NATO was made up of only 12 countries:...