"The story goes back more than three decades to the fall of the Berlin Wall and eventual re-unification of Germany. At the time, the Soviet Union had some 380,000 troops in what was then the German Democratic Republic, or East Germany. Those forces were there as part of the treaty ending World War II, and the Soviets were concerned that removing them could end up threatening the USSR’s borders. The Russians have been invaded — at terrible cost — three times in a little more than a century. So in the early 1990s, West German Chancellor Helmut Kohl, U.S. Secretary of State James Baker, and Soviet General Secretary Mikhail Gorbachev cut a deal. The Soviets agreed to withdraw troops from Eastern Europe as long as NATO didn’t fill the vacuum, or recruit members of the Soviet-dominated Warsaw Pact. Baker promised Gorbachev that NATO would not move “one inch east.” The agreement... was followed in practice. NATO stayed west of the Oder and Neisse rivers separating Germany and Poland, and Soviet troops returned to Russia... But President Bill Clinton blew that all up in 1999, when the U.S. and NATO intervened in the civil war between Serbs and Albanians over the Serbian province of Kosovo. Behind the new American doctrine of “responsibility to protect,” NATO opened a massive 11-week bombing campaign against Serbia... From Moscow’s point of view, the war was unnecessary. The Serbs were willing to withdraw their troops and restore Kosovo’s autonomous status. But NATO demanded a large occupation force that would be immune from Serbian law, something the nationalist-minded Serbs would never agree to. It was virtually the same provocative language the Austrian-Hungarian Empire had presented to the Serbs in 1914, language that set off World War I... But NATO didn’t stop there..."