Why did the Germans lose WWII?

When analyzing the Second World War, the question of how the Germans managed to lose despite their stunning military success through June 1940 immediately comes to mind.  The string of German victories in the Soviet Union the following year gives the impression that the war was decided in the winter of 1941, if not later.  Although the actual "turning point" certainly occurred in the East, such a judgement relies only on the outcome of specific military engagements and does not address the underlying strategic decisions that led to such decisive battles in the first place. This outline looks at the strategic implications of Hitler's decisions in relation to four key events in 1940: the invasion of Norway, the so-called "halt order" at Dunkirk, the conduct and timing of the Battle of Britain and the decision for Operation Barbarossa.
  
In the opinion of the author, despite the illusion of German military triumph that lasts well into 1942, Hitler's decision-making in 1940 ensured Germany's ultimate defeat.      

The following is a brief, but detailed 4 point outline and attached bibliography.