Pretty much everyone who has been paying attention has heard by now that JS MCain promised not to go into Pakistan and apprehend Osama bin Laden even if he knew exactly where he was. Evreyone also knows that subsequent to this promise McCain received the coveted endorsement of al Qaeda. Let'e not rush to judgment and fall into the old post hoc ergo procter hoc fallacy. Just because the promise preceded the payoff, it does not follow that there was any kind of tit for tat. Al Qaeda simply supports candidates that it believes are best for its agenda. That's all. The promise had no impact.
On the other hand, if there is a terror attack conveniently timed to help McCain after one of his surrogates suggested some months ago that a terror attack would be helpful, I might start to wonder if a deal hadn't been cut. Still, it could just be a coincidence.