"evidence, that al-Qaeda has any chance to take over Iraq---ever."

You will wait a long time, like anything else that may, or may not, occur at some point in the future there can be be no "evidence" presented prior to that event occuring.

By all means, "pick a counterexample to Operation Barbarossa", although I do not know for what purpose. Considering Churchill's well publicised views on communism the immediate alliance between the UK and the USSR that followed Hitler's invasion is a classic example of "The enemy of my enemy is my friend". In exactly the same vein the outnumbered Sunni Arabs in Iraq, in the event of there being a civil war, if they are fighting against the Shiia Arabs backed by Iran, will not give a tuppenny-ha'penny damn about who comes to their aid and fights alongside them.

You asked me how they could take over in Iraq in the event of US Forces leaving. I stated that it could be possible in exactly the same way that the Ba'athists took over Iraq. It is possible, after all almost everything is possible. Ask me if it is probable and I would say no, it is not probable because Al-Qaeda is not really in the business of running countries. Having said that, if with Al-Qaeda help and Saudi money, the Sunni Arabs in Iraq managed to defeat the Shiia Arabs of Iraq in their civil war. Would the resultant Iraqi Government be better disposed towards Al-Qaeda? In those circumstances I would certainly suppose so.

When did I ever say that the Saudi Regime sympathised with Al-Qaeda. The initial reason for Osama bin Laden's hatred of the US was down to the fact that when originally threatened by Saddam in 1990, the rulers of Saudi Arabia turned down ObL's offer to use his Mujihadeen to defend Saudi and opted for the UN coalition led by the US instead.