It's a moral imperative, it's an economic imperative, and it is a security imperative. For we've seen how spikes in food prices can plunge millions into poverty, which, in turn, can spark riots that cost lives, and can lead to instability. And this danger will only grow if a surging global population isn't matched by surging food production. So reducing malnutrition and hunger around the world advances international peace and security - and that includes the national security of the United States.

For me, personally, the most difficult moments had to do with not just terrorist attacks, but also shootings.

Year after year, an ideological and economic barrier hardened between our two countries, meanwhile, the Cuban exile community in the United States made enormous contributions to our country, in politics, in business, culture and sports.

It's up to [Angela Merkel] whether she wants to stand again and then ultimately, it'll be up to the German people to decide what the future holds. If I were here and I were German and I had a vote, I might support her.

There are very few moments in our lives where we have the privilege to witness history taking place. This is one of those moments. This is one of those times.

What we can do is to shape how that process of global integration proceeds, so that it's increasing opportunity for ordinary people, so that it's creating better jobs, so that we are strengthening protections for workers, so that we are addressing some of the environmental challenges that come with rapid growth.

Part of what's unique about climate change, though, is the nature of some of the opposition to action. It's pretty rare that you'll encounter somebody who says the problem you're trying to solve simply doesn't exist. When President Kennedy set us on a course for the moon, there were a number of people who made a serious case that it wouldn't be worth it; it was going to be too expensive, it was going to be too hard, it would take too long. But nobody ignored the science. I don't remember anybody saying that the moon wasn't there or that it was made of cheese.