Forgive me if this has already been addressed, but the constitution says that congress is the only one that can declare war (important point). The US Military is acting as a force of the UN. As of now the United states has not declared war against them, we are just enforcing the UN no-fly. The US is not at war with them, the UN is. As part of our membership with the UN we are obligated to assist them. Thus the US has not declared war on anyone, only the UN has, so Obama doesn't need permission from anyone to lead his troops.
In any event if you guys think this would get anyone impeached then your a bunch of idiots. Bush did the same thing (invaded Iraq), along with many others. Hope y'all enjoy Glen Beck, be sure to grab your Iodine tablets and stockpile ammo.