The outbreak of the Second World War on September 1, 1939, when the Nazi Third Reich invaded Poland, is one of the events annually commemorated throughout Europe. However, September 17, 1939—the date of the Soviet Union's aggression against Poland—is not as widely known in the West. I believe this event needs to be remembered, as it not only decided the fate of my homeland and other countries of Central and Eastern Europe, but it did so for the whole of the next half century. If today we Poles, and other peoples of our region, repeat that we know Russia and...