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.

Al-Qaida in particular remains dangerous, and there [in Iraq] is some residual militia and special group presence. There are still between 20 and 30 attacks per day, still periodic car bombs and still loss of innocent civilians.

Items of interest will be located, identified, monitored, and remotely controlled through technologies such as radio-frequency identification, sensor networks, tiny embedded servers, and energy harvesters - all connected to the next-generation internet using abundant, low-cost, and high-power computing.

The Islamic State fighters in Mosul are dead men walking and I think they increasingly know it.

Let's remember that the reason we are there is that we have vital interests in Afghanistan, hugely important national interests, as do the other countries involved.

First and foremost is to not allow the reestablishment, if you will, of an extremist sanctuary that can export the kind of terror that ended up with terrorists taking down the World Trade Center and plowing into the Pentagon and a field in Pennsylvania. That's the point: We started this war because the Sept. 11 attack came from this area. And we do not fight alone, but with some 40 allies who share that view.

The task [in Afghanistan] is to reduce civilian casualties while still not hesitating to respond to enemies who are trying to kill our soldiers.