Of course you can't control that. But when it has a history of being effective, and working in this case as well, it is just plain stupid to come out and rule it out as an option. It is even worse when folks like Bush or McCain then call those who would use this option appeasers, or compare them to Neville Chamberlain. It is especially ridiculous when Bush turns around opts for the exact same policy he's previously criticized. The bottom line is diplomacy worked even while the administration and McCain were busy whooping up a frenzy against it calling it appeasement.
It's obviously Bush putting another feather in his cap, to quench the nay-sayers concerning his failed policies. McCain may benefit, claiming to build on it. Seriously, the jury is still out on this situation, whether it is genuine progress or just prolonging the party.