After the German invasion of the Soviet Union and the entry of the USA into the war, the alliance of the "Big Three" was formed (Churchill, Roosevelt, Stalin). The operations of the Western Allies were focussed first on combating German submarines, particularly in the Atlantic, and on the continually intensifying strategic bombing campaign, which to an increasing degree also began to strike the German civilian population in the cities. The main thrust of the Western Allies did not begin until the invasion of Normandy on June 6, 1944. By the end of the year large areas of Western Europe had been liberated from German occupation. On the Eastern front the Red Army finally seized the military initiative in the course of 1943 in equally embittered battles with enormous numbers of casualties. Despite the hopeless military situation, Hitler continued the war with dogged determination - until the capture of the Berlin Reich Chancellery by the Red Army. Up until this point Germany had only been subjected to aerial warfare, but in this final phase of the war, it became the scene of senseless ground fighting with high casualties. After Hitler's suicide on April 30, 1945, the German Wehrmacht (German armed forces) capitulated during the night of May 8 - 9, 1945.