The decline and fall of the American empire

I spent less time on China in the book because most people exaggerate China's importance. China is still a relatively small country economically with an economy smaller than California's. Ten years from now China will be an Italy with nuclear weapons. Once you get into the second quarter of the century, 2025 and beyond, then China starts to begin to take its place as one of the top-ranking countries. Then, you might spend a lot more time worrying about China.

But, what do I think the most volatile relationship will be, the one that changes most this decade? It's U.S.-Europe.

How will that affect ordinary Americans? What changes will we see if it's not a military threat? I mean, the American people can't see past terrorism right now because we can see very clearly what that threat is.

I'd say that right across the board there are some consequences. The trade and investment with Europe is very strong and healthy. If that becomes politicized it could be a problem. There are already looming disputes over biotech, bioengineered greens.

The disputes on other areas -- on the Middle East, on Iran, on Iraq -- could lead to trouble. NATO, which has been our main tool in influencing Europe, is withering on the vine, partly of our own doing. We're just losing interest in Europe.

I'd probably put it in these terms: Europe will be our competitor but not necessarily our adversary. That's why we're in a switching point where we really have to get it right. Negotiating a treaty, rebuilding Afghanistan, dealing with the Middle East process -- all that stuff usually moves forward with the U.S. taking the lead and Europe backing off. If we wake up one day and the U.S. tries to take the lead and Europe tells us to take a hike, then we're in a brave new world. Doing business on a day-to-day basis becomes much more difficult. At the broadest level, all the money and lives that we expended since World War II to tame the international system and give it a benign character -- all of that's at stake. It's possible that we could wake up and it will be 1935 and I don't think any American wants that.

You do say that the unipolar world that we have now is a peaceful one and historically unipolar worlds are always peaceful. You say that a world without American primacy will be an unpredictable and unpleasant world. For everyone, or just for Americans?

Everybody. Even though a lot of countries wouldn't necessarily say so, they've had a pretty good deal. Big Daddy's been there and he takes care of everything. The Europeans don't have to spend much on defense. China and Japan basically don't like each other, but they're not gnawing at each other's heels because the U.S. keeps a presence there. We provide stability. What we're seeing now is the end of that. The U.S. is decamping from Europe because we've got nothing else to do there, but it does leave the Europeans with the new onerous task of taking care of themselves. That's going to be scary for them even though there's a certain schizophrenia. The Europeans are annoyed with us but scared of what Europe will look like without the American pacifier. In the same respect, the Saudis believe that the U.S. destabilizes them but what happens if the U.S. leaves? The stakes are very high.

I'll take a wild guess that most Americans will be surprised that Europe might challenge us. Are Europeans?

Depends on what you mean. They will never be a superpower; they're never going to spend the money to rival the U.S. in military terms. What we'll see is that they will build up enough capability to take care of the Balkans and other small conflicts, and the U.S. will take care of other parts of the world. Sort of a division of labor. But that division of labor means the end of the Atlantic alliance.

You say most Americans will be surprised at this and I think that's right. I don't think most Europeans will be. This issue gets much more traction there. They are engaged in international issues in ways that we are now. There is this abiding sense that we're all in the same family, that these are our cousins. That's probably what will keep us from going to war, but it's not going to keep us from drifting apart.

So how do you fear that America might react to this?

The worst that we can do is bite back. The historical analogy that is most useful here is what happened in the 19th century when America rose because it federated. Basically, history is reversing itself: This time we're at the top and Europe is coming together, last time Europe was at the top and we came together. There wasn't war over America's rise because the British made room for us. They cut deals on all kinds of issues and they said we need to have a rapprochement with the rising great power, America. We ought to do the same thing.

We ought to say: Europe is rising, Europe wants voice, influence, and we're going to make room. I don't think that we've been doing that. We're still in the mode of "How dare you challenge us?" Probably the best anecdote is about the E.U. Defense Force. The U.S. fought the war over Kosovo, and then Congress said, "This is ridiculous. This is not our problem. Europe, you need to spend more and build your own military." So Europe said, "OK." And then the U.S. went bonkers: "What do you mean you're going to build your own military? You don't love us anymore?"

Europe is growing up and leaving home to go to college and we're just not ready for it. We ought to say, "Go to college, be independent, and just call us once a year or something."

But you don't think that terrorism is the unifying great threat that it's been made out to be?

No. Everyone was saying, "Aha, the Pearl Harbor of the 21st century!" This couldn't be further from the truth. We have quite rapidly drifted back to disengagement.

Couldn't a couple more attacks change that?

Yes. That's the big unknown. If a nuclear weapon goes off, God forbid, if there's another catastrophic attack, then I think we're in a brave new world. Do I think it will bring the country together and make us internationalist? I don't know. It could also make us pull in and retreat. It's dangerous to be confident that terrorism is the sort of threat that will keep us engaged in the world. It does the opposite -- pushing us to both unilateralist and isolationist extremes.

• View blog reactions