You ought to have a theme issue on “America as a global threat to health” suggested one of our correspondents, perhaps facetiously. Imagining the downcast face of our North American editor, the plummeting circulation of BMJUSA, and the wagging finger and circumlocutions of Donald Rumsfeld, we promptly decided against. But this issue could have provided the beginnings for such a theme.

A serious response to global warming needed American leadership. Instead, we got the opposite. The United States, which produces a quarter of the world's greenhouse gases, turned its back on the Kyoto agreement. As a result we are not …