Not really. Congress can refuse to budget a prospective military adventure, for example.
Bush needs to improve his personal credibility before he can comvince the american people that the USA should attack another country. Right now, he doesn't have the credibility.
He has the power, but doesn't have the public support to use it in the way you suggest.
Nice theory but rarely done in fact.
It will be a natural progression of pressure with NATO involved.
The Dems have already committed to being tough guys regards Iran and they can't afford another spineless episode in the foreign policy area.
In Foreign policy, the Democrats have the credibility problem.
Ironically, the Iranian situation gives the Dems a chance to shine their sabers for full effect and reap electoral benefits.