Before Operation Barbarossa was launched, Hitler and Germany have great success on invasion and battles, except Battle of Britain. Hitler invaded Poland in 1931, attacked Belgium, France, and Holland, battle with Britain. But when he comes to invading Soviet Union, the operation was the beginning of Hitler’s downfall. Operation Barbarossa is a code name for German’s invasion of USSR. That operation was launch on June 22, 1941, and because it was launched at that time, Germany has to deal with one of the biggest problem when they were invading Soviet Union – winter. It was the largest military attack in World War Two. Operation Barbarossa was the turning point of World War Two, and reason why is because the invasion of Soviet Union is one of the biggest mistakes Hitler makes in World War Two. The idea of invading Soviet Union is not the problem, but the way Hitler did it. Operation Barbarossa failed because Germany used weak military forces, had poor logistics and planning, and failed to win the Battle of Stalingrad, which is one of the main battles in Operation Barbarossa.