relocated Soviet border on June 22, 1941, in the opening stages of Operation Barbarossa. The poor Soviet performance in the Winter War against Finland encouraged Hitler to ignore the terms of the Molotov–Ribbentrop Pact and take the Red Army by surprise. During the initial stages of the war, Soviet forces were often ordered to stand their ground despite limited defensive capabilities, resulting in numerous encirclements and correspondingly high numbers of casualties. The United States program of lend-lease was extended to Soviet Union in September 1941, supplying planes, tanks, trucks and other war materials. Eventually the Soviets managed to slow the Wehrmacht's blitzkrieg, halting the Nazi offensive in December 1941 outside the gates of Moscow, in part because mobilized troops with winterized clothing from Siberia were transferred from there after Stalin realized that Japan was not going to attack the Soviet Union (Japan had just attacked Pearl Harbor). The Red Army launched a powerful winter counteroffensive which pushed the Germans back from the outskirts of Moscow. At the start of 1942, the weakened Axis armies abandoned their march on Moscow and advanced south towards the Caucasus and Volga river. This offensive, in turn, ran out of steam in autumn 1942, allowing the Soviet forces to stage a devastating counteroffensive on the overextended enemy. The Red Army encircled and destroyed significant German forces at the Battle of Stalingrad, which ended in February 1943 and reversed the tide of the war in Europe. In the summer of 1943, following the Battle of Kursk, the Red Army seized the strategic initiative for the remainder of the war. All Soviet territory was liberated from Axis occupation by 1944. After having driven the Axis armies out of Eastern Europe, in May 1945 the Red Army launched its assault on Berlin, which effectively ended World War II in Europe (see V-E Day). Much of Eastern Europe and great parts of the Soviet Union were devastated by Red Army troops as a result of an aggressive policy of "scorched earth". Once Germany had surrendered, the Red Army joined the war against Japan, and in summer 1945 carried out an offensive against Japanese forces stationed in northern Manchuria. The Red Army emerged from the war as one of the most powerful land armies in history with five million soldiers, and more tanks and artillery than all other countries combined. The defeat of the Wehrmacht had come, however, at the