What if Hitler had poured, into North Africa, the troops and supplies which he sent later in the war?
As I see it the Germans would have been able to push through to and past the Suez. Then they would control the oil fields that they needed. Thus the invasion of Russia, if it had to occur would have just been a strait thrust at Moscow, then St. Petersburg and the Caucusus could have been captured, since the Germans now had the main rail hub and more oil.