President can, legally, use the military in combat operations (including sending Tomahawk missiles into an airfield in Syria) without congressional approval, or even letting them know he's going to do so in the first place There has been a lot of discussion about whether or not the attack on an airfield by American Tomahawk missiles in early April of 2017 was a constitutional action by President Donald J. Trump, despite the fact that the military action occurred prior to the President receiving some kind of congressional approval for it.