Does Bush have one more war in him?

Reports have the U.S. Government taking moves to declare the Iranian Revolutionary guard a terrorist organization. This is considered significant mostly because this is the first time the designation will be applied to an agency of a foreign government.

Yes we know the Revolutionary Guard is likely funding and supplying Iraqi insurgents, but when you are trying to open a dialogue on the future of Iraq with Iran, talk of a terrorist label for the Guard does not seem to be helpful.

Is this just more saber rattling or is it a real move to set up new justifications for another war?