Correct, last Fall The congress passed a bill Authorizing the President to take action against IRAQ if they don't disarm.
Now it's up to the President to determine if it is necessary to use force to protect the USA.
Of course they did, but this bill passed by Congress was not necessary. The President is the Commander In Chief, and can deploy troops and put them into action as he sees fit. Formal declarations of war STILL need to be made in Congress. I believe the last formal declaration was WWII
Let's not forget that Iraq is also in violation of the terms of cease fire from the first Gulf War. The President does not need another declaration to continue a conflict already declared.
But either way, Bush is easily covered.