In March 1938, Germany sent its army into Austria, known as the Anschluss, which had only a little reaction from European countries. Shortly after that, the Allies agreed to give Sudetenland, part of Czechoslovakia, to Germany, so that Hitler would promise to stop taking more land. But the rest of the country was either forced to surrender or invaded by March 1939. The Allies now tried to stop him, by promising to help Poland if it was attacked. Just before the war, Germany and the Soviet Union signed a peace agreement, agreeing that they would not attack each other for ten years. In the secret part of it, they agreed to divide Eastern Europe between them.