As the title says-
It's sometime in early 1941 and Hitler, predicting that the poorly led Italian military won't do well in Africa, decides to invade Turkey (in order to open up a second front against the British in Africa and eventually take the suez canal).
In addition, realizing that the Italian navy is no match for the British navy, realizes that its absolutely necessary to take Gibraltar. Because a seaborne invasion is essentially impossible, he gives an ultimatum to Nationalist Spain that it has to give the Axis military access to attack Gibraltar or be annexed.
The overall strategic goal is to seize Gibraltar and the suez with land-based armies. Once these objectives are complete, the German army will be relocated to the eastern front as quickly as possible in anticipation of a probable soviet betrayal.
For the sake of the example, we can assume that Germany diverts a sufficient number of fighters and naval bombers to prevent the Bosphorous strait from being blocked by the British Navy.
Germany also leaves a sizable defensive army on the eastern border of Poland to dissuade the soviets from breaking the NAP.
My personal assessment [feel free to disagree with this] is that most people agree that the soviets would have broken the pact eventually (or Hitler would be forced to for ideological reasons). However, most people also agree the soviets weren't ready for war in 1941 (the officer purge) and therefore Stalin would have waited to at least 1942 to invade Germany. So the question IMO is, can Germany take the Suez/Gibraltar before the end of 1941?