Under the guise of living space, Germany invaded Poland on 1 September 1939. After quickly breaking through Polish defenses and proceeding to encircle and bombard Warsaw, the Germans surrendered with Germany gaining almost half of Poland by 27 September of the same year. Another example is Operation Weserubung, on April 20, 1940 German forces invaded Denmark, fearing potential repercussions from opposing Germany, Denmark ordered its troops to withdraw and not engage the rapidly advancing invasion forces, in Overall the invasion lasted only six hours, the shortest campaign in the war. However not all military campaigns under Nazi Germany were a success, their most infamous failure being Operation Barbarossa, also known as the invasion of Russia. Since Germany and Russia's political visions were polar opposites, it was only a matter of time before their fragile alliance crumbled and one betrayed the other. On June 22, 1941, Germany invaded Russia with approximately 3.5 million troops, made up of German, Finnish and Romanian soldiers. With the invasion forces entering and pushing through the disorganized Russian army, it was initially a great success, with over half a million Russian casualties and pushed 200 miles into enemy territory. The plan began to fail in December, when the Russian winter began to emerge, as the German soldiers were unprepared for the harsh winter they would face. As winter arrived, the attackers were ill-equipped to fight the Russians and their advance stalled, losing momentum and effectiveness, giving the Russian forces the opportunity to mount a counterattack to repel the invading army. With the Russian counterattack, German forces began to lose ground and were pushed back from Moscow. Not being able to take the country's capital and with the loss