John Kerry: “It is a lot easier to push back against an Iran that doesn't have a nuclear weapon rather than one that does.”

We are competing, but everybody has their own approach, which is one of the exciting things here.

The Administration is determined to try to stabilize what has been, particularly recently, a very unstable situation.

What we are trying to achieve now is really to establish some stability if we can, in the relationship, without conceding anything.

It's a matter of mathematics and physics, not politics, not ideology. It is a response to the science.