I think graffiti is part of Berlin culture. You think about what the Berlin wall meant and how visible that was in everyone's life. How it was a part of their very identity.

We don't gaze into a crystal ball. I do not believe that we predict things. I think political science is bad at prediction. I think what we really do well is in a number of instances where politics matters, we can do a better job of tell you what is happening now, than other people. So, we can look at Syria today. We can look at the Eurozone today. And we can look at areas where politics is a driver and we can give you a pretty good sense in those areas of here is how to understand today.

I would rather people not smoke. I certainly appreciate the fact that smoking is not legal in restaurants and bars. That used to stop me from going out at night because you'd go someplace and your clothes would reek and you wouldn't enjoy the experience and that affects your rights. It's always a question. Whenever you are talking about these issues, it's not a question of restricting rights. It's a question of restricting whose rights, and providing for whose rights and that's a tricky balance.

The real question is not are there other forms of life in the universe, but are there other intelligent forms of life out there right now. Because the universe is not only really big but it's also really long. It's been around for a long time; it's going to be around for a long time.

I would rather people not smoke. I certainly appreciate the fact that smoking is not legal in restaurants and bars. That used to stop me from going out at night because you'd go someplace and your clothes would reek and you wouldn't enjoy the experience and that affects your rights. It's always a question.

Climate is a global issue. Coal is still the energy that is being used more than anything else to make electricity. The United States is using less as we're turning more to gas. But, around the world, that's what they're using.

In the nearer term, the likeliest source of risk is a conflict between China and the U.S. These are now the two largest economies in the world, and the combination of their economic interdependence, the sharp differences in their political and economic values, and the growing divergence in their interests makes this relationship potentially dangerous for everyone who might be affected by it - which means pretty much everyone.