half a declaration of war

The House Armed Services Committee is marking up a defense authorization bill that contains the following language:

DECLARATION OF POLICY.—It shall be the policy of the United States to take all necessary measures, including military action if required, to prevent Iran from  threatening the United States, its allies, or Iran’s neighbors with a nuclear weapon.

This provision follow a long list of threatening behaviors by Iran. The good news is that this language seems to endorse military action only if Iran has an actual nuclear weapon and is threatening the United States or its allies. The bad news is that this sort of language can be taken by the Executive Branch as the functional equivalent of an authorization of force or declaration of war -- as the Bush Administration did with similar language passed in the Clinton Administration.  We should do these things with our eyes wide open.