If a cat sits on a hot stove once, it will never sit on a cold one either.

NATO is still the most remarkable alliance in history. It stuck together through 40 years of Cold War, and it then joined together to fight in Afghanistan. In the 1980s, I would not have thought this was going to be possible.

It's hard to conceive that it would take more forces to provide stability in post-Saddam Iraq than it would take to conduct the war itself and secure the surrender of Saddam's security forces and his army. Hard to imagine.

Every math curriculum in the world is based on the idea of hand-calculating, and most of what you're teaching is how to calculate. And I think the resistance to this is very variable.

There has been a good deal of comment — some of it quite outlandish — about what our postwar requirements might be in Iraq. Some of the higher end predictions we have been hearing recently, such as the notion that it will take several hundred thousand U.S. troops to provide stability in post- Iraq, are wildly off the mark. It is hard to conceive that it would take more forces to provide stability in post-Saddam Iraq than it would take to conduct the war itself and to secure the surrender of Saddam's security forces and his army — hard to imagine.

Putin is behaving in a very dangerous way. And Donald Trump sounds as though he would simply sit back and allow that to go on. I worry about where that would end up.

If a cat sits on a hot stove once, it will never sit on a cold one either.