In article 2 section 2, provides that the president is commander-in-chief of the armed forces. The general interpretation of which is that the president is granted the power to initiate military action, because the president tends to work faster than congress in time-sensitive situations. The power was further clarified with the War Powers Act. Which gave the president the ability to wage war for 90 days (60, plus 30 withdrawal) without the approval of congress. In practice, however, congress tends to pay little attention to these deadlines. While we have engaged in over 100 military conflicts in our country’s history, actual war has been declared only 5 times. Two years ago, the president initiated a bombing campaign against Libya, very similar to what he is proposing now, without congressional approval. I’m not quite sure why people are freaking out about this action, when it has been made clear that there is no intention of involving troops. As for why he’s asking for congressional approval… my theory? He’s playing chicken with Assad. He is trying to threaten him into handing over chemical weapons and starting peace negotiations with the US backed- Syrian rebels.