In the nearer term, the likeliest source of risk is a conflict between China and the U.S. These are now the two largest economies in the world, and the combination of their economic interdependence, the sharp differences in their political and economic values, and the growing divergence in their interests makes this relationship potentially dangerous for everyone who might be affected by it - which means pretty much everyone.

The United States is not longer going to be the world's policemen and our days of determining you're in or you're out around the world no matter what the level of direct American interest or connection are going to be very limited. Increasingly, Africa will be doing that.

There is too large a divergence at the moment in the interests and values of the world's most powerful states.

It's very hard for someone who makes $1,000 a year or some who makes less than $1 a day to care about the environment.

I think that the environment is very a complicated question. I am very sympathetic to people who support the environment who live in the United States. I am very sympathetic to people who don't support the environment who live in a very poor country.

Climate is a global issue. Coal is still the energy that is being used more than anything else to make electricity. The United States is using less as we're turning more to gas. But, around the world, that's what they're using.

In environments where corporations become too interventionist and capture regulation themselves, the government must be able to battle back so that the people have a chance.