John Kerry: “It is tough, tough work, as complex and as challenging as any foreign policy challenge that we have today.”

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

I know President Biden feels very strongly about living up to our commitments, and our values.

no country can solve the climate crisis alone. This requires multilateralism automatically.

Depending on what it involves, shadow diplomacy has also saved us from a war.