I think, the argument sometimes that I've had with folks who are much more interested in sort of race-specific programs is less an argument about what is practically achievable and sometimes maybe more an argument of "We want society to see what's happened, and internalize it, and answer it in demonstrable ways." And those impulses I very much understand.

Yes, this is hard. But there should be no question that the United States of America is stepping up to the plate. We recognize our role in creating this problem; we embrace our responsibility to combat it. We will do our part, and we will help developing nations do theirs. But we can only succeed in combating climate change if we are joined in this effort by every nation - developed and developing alike. Nobody gets a pass.

Just as black anger often proved counterproductive, so have these white resentments distracted attention from the real culprits of the middle class squeeze - a corporate culture rife with inside dealing, questionable accounting practices, and short-term greed.

People are less certain of their national identities or their place in the world. It starts looking different and disorienting. And there is no doubt that that has produced populist movements both from the left and from the right in many countries in Europe.

I do make sure that I've got people who are experts that are helping me make the best decisions possible.

We have to be successful at the cutting-edge industries of the future like Twitter. But we also have always been a country that makes stuff.

Look at Chancellor [Angela] Merkel, her personal story helps to tell a story of incredible achievement that the German people have embarked on and I think is something that you should be very proud of.