[Huck]

The President can take a foreign policy action.

Can you show me what Constitutional power you are referring to? I can't find it.

[hchutch]

I think it was Article II, the President being Commander-in-Chief. IIRC, the Supreme Court also ruled that the President had plenipotentiary powers (might be the Curtiss-Wright matter referred to elsewhere in this thread) in matters of foreign policy.

When Congress is not in session, who makes the call? The President. If Congress does not like certain actions, they can pass legislation concerning it. See the Boland Amendments of the 1980s as one exhibit of that.