I'm as dumb as Niall Ferguson

IDEAS: But you supported the invasion of Iraq.

FERGUSON: I argued that if it was to be done, it should be done well or not at all. But I didn't oppose it. With the benefit of hindsight, I regret that. It was a disaster to commit so few troops and to have no coherent plan for reconstruction. It was in defiance not only of British imperial history but of successful American occupations-for example of Germany, Japan, and Korea, where the United States stayed long enough to change institutions.

But typically, American interventions last only a few years. In the case of the Middle East, the result will be turning Iraq into a Haiti on the Tigris.

IDEAS: How do you understand radical Islamism? Is it, as some say, the successor to Marxism?

FERGUSON: It is. The great category error of our time is to equate radical Islamism with fascism. If you actually read what Osama bin Laden says, it's clearly Lenin plus the Koran. It's internationalist, revolutionary, and anticapitalist-rhetoric far more of the left than of the right. And radical Islamism is good at recruiting within our society, within western society generally. In western Europe, to an extent people underestimate here, the appeal of radical Islamism extends beyond Muslim communities.

IDEAS: To people who might once have been drawn to Marxism?

FERGUSON: And for much the same reason. Here is a way to reject the impure, corrupt qualities of western life and embrace a monotheistic zealotry. That's very satisfying.

IDEAS: Why is Europe more vulnerable than the United States?

FERGUSON: The United States has at least two religions, one being religion per se, the other being the civic religion of the Constitution. These are powerful integrative forces. To become an American is a transformative experience, and I'm impressed by it. It doesn't happen in Europe. Immigrants remain deeply alienated, plus they're not integrated well into the economy. And that's a dangerous situation.

I was a half-hearted supporter, and I'm sorry, too. As for American integration, I've heard the argument. I hope he's right.