Obama knows he can't really "defeat" ISIS. We should understand that too.

Always, always, always, in every war, every fight, everywhere in time, the expenditure of force is never sufficient. Success is fundamentally the result of political change secured in part by the use of force. It is therefore not terribly interesting to say, “We cannot fight our way to peace in Iraq and Syria.” Obviously so. That’s why Obama has been reluctant to do anything there in the first place.

Politics — political change — is one reason why Obama waited until Iraq chose a president who promised to be more accommodating to Sunnis before he committed to a major counter-terrorism campaign. Obama did put politics first; he helped push Nuri al-Maliki from power. By no means was this a sufficient step, but it was a necessary one.

I suspect that a larger military campaign against ISIS is similarly imperative, but it will not be decisive.

I also suspect that the White House does not know how to explain to the country that in order to understand what he is doing, the American people must change the way they understand basic concepts of war and peace.