“When the wall came down in the Soviet Union and Europe, [Soviet President Mikhail] Gorbachev destroyed himself politically by doing something that was very, very courageous. He went to [President George H.W.] Bush. He said, ‘I’m going to allow you to reunify Germany under a NATO army. I’m going to remove 450,000 Soviet troops. But I want your commitment. After that, you will not move NATO one inch to the east.’ And we solemnly swore that we wouldn’t do it.”