What was Germany's two-front war plan in World War 2?

The plan, called the Schlieffen Plan, was to occupy Western Europe, then defeat the Soviet Union.

During the early part of the war, Hitler hoped to sue Britain for peace following Dunkirk and the battle of Britain. German military planning was based on the idea of blitzkrieg, which meant a short war. When Hitler attacked the Soviet Union on June 22, 1941, he hoped to defeat the Russians within 3 months and before the onset of winter.

Following the failure of this, Germany was faced with a long war, and the entry of the US in December 1941 meant that Germany was faced with a true two-front war. Hitler and the German High Command's hopes of victory were now placed in the idea of crushing the Soviet Union's armies and reducing Britain into submission via a submarine blockade. This would leave the US confronted by a Fortress Europe impossible to assault. However, the tide of battle turned on the Eastern Front at Stalingrad in November 1942, and in the Atlantic in March 1943. Following the initiative being passed to the Allies, Hitler was thrown back on his belief in secret weapons that could swing the war back in Germany's favor. Despite the fact that Germany invented the first jet aircraft (the Messerschmitt Me262) and the V-1 and V-2 rockets (the first cruise missile and the first ballistic missile), these were created too late to affect the war's outcome, and defense of the German Reich became impossible.