Don't forget Yemen, where there are also extremist elements, as we saw recently.

This cannot be the United States being the air force for Shia militias, or a Shia on Sunni Arab fight.

The president and I sat down in the Oval Office, and he expressed very clearly that what he wants from me is my best professional military advice.

I am not a politician, and I will never be, and I say that with absolute conviction.

I think Putin wants to recreate as much of the Soviet Union as he can through a variety of different means. He's invaded parts of Georgia, took Crimea, southeastern Ukraine, bases in other countries.

We cleared many of their towns and cities and rural areas of al-Qaida Iraq and other insurgents.

I think no commander ever is going to come out and say, 'I'm confident that we can do this.