Over more than a decade, Iran had moved ahead with its nuclear program. And before the deal, it had installed nearly 20,000 centrifuges that could enrich uranium for a nuclear bomb.

Winston Churchill used to say that we, Americans, try every other option before we finally do the right thing. After everything else is exhausted we eventually do the right thing and I think that's true for Congress as well. And it's important for Americans to remember that politics has always been messy.

I want to thank the Greek people publicly for their humanitarian response to the crisis of so many migrants and refugees seeking safety in Europe. Greeks, especially on the islands, have shown extraordinary compassion and they've rightly earned the admiration of the world.

I don't think we should ever accept the idea that someone can come along and take away our safety and our freedom.

Ultimately, peace is just not about politics. It's about attitudes; about a sense of empathy; about breaking down the divisions that we create for ourselves in our own minds and our own hearts that don't exist in any objective reality, but that we carry with us generation after generation. And I know, because America, we, too, have had to work hard over the decades, slowly, gradually, sometimes painfully, in fits and starts, to keep perfecting our union.

There is not a liberal America and a conservative America - there is the United States of America. There is not a black America and a white America and latino America and asian America - there's the United States of America.

We did not come to fear the future. We came here to shape it.