There are always things that I think I wish I could have done better.

People of Berlin - people of the world - this is our moment. This is our time.

Leaving the broken system the way it is, that`s not a solution.

When we helped prevent the massacre of civilians trapped on a distant mountain, here's what one of them said: "We owe our American friends our lives. Our children will always remember that there was someone who felt our struggle and made a long journey to protect innocent people." That is the difference we make in the world.

By some estimates, the oil you recently discovered off the shores of Brazil could amount to twice the reserves we have in the United States. We want to work with you. We want to help with technology and support to develop these oil reserves safely, and when you're ready to start selling, we want to be one of your best customers.

One of the hardest things in politics is to convince people to do things now that will have a good effect 20 or 30 years from now because politicians tend to have a short-term view. They are more attentive to things that people care about today.

The biggest threat that we face right now is not a nuclear missile coming over the skies. It's in a suitcase. This is why the issue of nuclear proliferation is so important. It is the - the biggest threat to the United States is a terrorist getting their hands on nuclear weapons.