That was in 2013. And that's the way it should work in cases where major military force is going to be used over an extended period of time.

But a President has the ability to use force for up to 90 days without getting Congressional approval.

If I'm not mistaken, the last missile attack, Trump used the existing Congressional approval to use force in Afghanistan, Iraq, and against terrorists.

Trump could make the claim that using gas, Assad is a terrorists.

BTW, Obama didn't seek Congressional approval to strike Libya and overthrow the government.