The United States alone produces a quarter of the world's emissions. It is in the Americans, in the first place, that we place our hopes of effectively limiting greenhouse gas emissions on a global scale.
One can go to war alone, but you can't build peace alone.
In an open world, no one can live in isolation, no one can act alone in the name of all, and no one can accept the anarchy of a society without rules, ... There is no alternative to the United Nations.