War Criminal?

First off this is not an attack on Bush, this is a laid out question. I am not a liberal hippie. The US went to war by invading Iraq and Afghanistan. In order for the united states to go to war you have to do what? Get it ped through congress which the Bush administration did not do. So my question is since he did not wait on congress doesn't that make him a war criminal? if anything this is just some food for thought or something to make ya think for a second so please don't bombard me with angry messages. I happen to support the US in all of its matters.