In light of the previous post, I'd expect president Obama's speech on ISIS today to sound fierce at first blush. But it will actually be a hollow speech, as toothless as sanctions against a few guys in Russia. The speech though, is meant for domestic consumption. It will be aimed at the casual political observer, delivered with the intention of strengthening Obama's crashing foreign-affairs approval numbers. Keep in mind, this is a political president, and a political speech. Don't expect the speech to have much in it that will deter ISIS or even give them pause for thought.
The thought process Obama will be trying to interrupt is not that of ISIS but rather the ever-increasing notion that he is a failure as a foreign policy president. He's trying to stem the tide of a potential Republican wave in the Senate, in November. He's not really going to do much stem the tide of ISIS. They aren't voters or even potential future voters, so their tide only matters insofar as it affects the opinions of voters at home.