The American people are pretty impressive in their ability to keep after something if they think it is doable.

It's a very bad thing when people exterminate other people, and people persecute minorities.

Islamic State is mainly a direct result of the failure in Syria. That's where IS has grown. That's where IS spread from.

That sense of what happened in Europe in World War II has shaped a lot of my views.

Donald Trump seems to be unconcerned about the Russian aggression in Ukraine. By doing this he tells them that they can go ahead and do what they are doing. That is dangerous.

One of the things that ultimately led me to leave mathematics and go into political science was thinking I could prevent nuclear war.

After a regime is removed, however, it is dangerous to leave a security vacuum.