I think the primary message to the world is that the United States is going to remain the strongest military power in the world.
One demonstration of extremists, any more than a Ku Klux Klan demonstration in the United States, is not necessarily reflective of what the rest of the country feels.
These days, it takes only seconds - seconds - for a picture, a photo, to suddenly become an international headline.
Rising sea levels, severe draughts, the melting of the polar caps, the more frequent and devastating natural disasters all raise demand for humanitarian assistance and disaster relief.
The United States, and the president's made this clear, does not want Iran to develop a nuclear weapon. That's a red line for us. And it's a red line obviously for the Israelis so we share a common goal here.
The last thing I want to do is to make the mistakes of the past.
The United States has to have the capability to deal with more than one enemy at one time and be able to confront them and win.
Go forward, knowing that you are greater than the challenges of your time.
Well, you know, any defense force worth its salt has to be able to deal with uncertainty, has to be able to deal with events that we may not have planned for.
When you cut a half-a-trillion dollars from the defense budget, it affects almost every area in the defense budget.
We either believe in the dignity of the individual, the rule of law, and the prohibition of cruel and unusual punishment, or we don't. There is no middle ground.
The area of climate change has a dramatic impact on national security.
The Taliban is resilient.
I know that young people sometimes, caught up in the moment, make some very foolish decisions.
Unfortunately these days, there is a hell of a lot that keeps me awake.
You know, as director of the CIA, I got an awful lot of intelligence about all the horrible things that could go on across the world.
After every major conflict - World War I, World War II, Korea, Vietnam, the fall of the Soviet Union - what happened was that we ultimately hollowed out the force, largely by doing deep across-the-board cuts.
I mean, the Taliban, my view is that they have been weakened. We have not seen them able to conduct any kind of organized attack to regain any territory that they've lost. We've seen levels of violence going down.
When you're smaller and leaner, you're not going to have that large a presence throughout the world.
An aggressor nation or extremist group could gain control of critical switches and derail passenger trains, or trains loaded with lethal chemicals.