During the Cold War, the U.S. didn't attack the Soviet Union when it invaded Hungary and Czechoslovakia. But we did make clear that we didn't accept their aggression as legitimate. That we'd fight to protect West Germany, Italy, and our other NATO allies. And that we knew they were on the wrong side of history. We were right and our stance emboldened reformers from Budapest and Prague to Bucharest — and Moscow. In my visits in all these countries over the last two decades, I've heard that time and again.