John Kerry: “Let me make it as clear as I can to all of you. That is just not true. This is about the world's red line.”

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

Obviously, we're already seeing ways in which it's going to affect people.

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

I mean, we try to help the world.