America must help Ukraine for the same reasons we helped Europe defeat Nazi Germany: Their fight is our fight. Thousands of Americans gave their lives 79 years ago to storm the beaches of Normandy. Their invasion brought down the Third Reich. Then-Gen. Dwight D. Eisenhower told the troops in his brief Order of the Day for June 6, 1944, that their victory would "bring about the destruction of the German war machine, the elimination of Nazi tyranny over the oppressed peoples of Europe, and security for ourselves in a free world." The same is true today. Morality alone compels us...