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

Poles understand perhaps better than anyone the consequences of making toothless warnings to brutal tyrants and terrorist regimes.

History is just littered with problems that were solved that were supposed to be impossible.

The most striking thing is that even before Osama bin Laden was killed, he seemed largely irrelevant to the Arab Spring.

I think one has to say it's not just simply a matter of capturing people and holding them accountable, but removing the sanctuaries, removing the support systems...

The Bernie Sanders phenomenon shows that it's not confined to Republicans. There is a general sentiment that America is on the wrong track.

I think, in the longer view of things, there is a very powerful pull in the direction of participatory government.