Richard N. Haass, president of CFR and head of policy planning at the State Department during the outbreak of the Iraq war three years ago, says that in hindsight, while history's judgment will depend on how things turn out in Iraq, the impact on U.S. foreign policy at this point is "clearly negative."

The war, he says, "has absorbed a tremendous amount of U.S. military capacity, the result being that the United States has far less spare or available capacity, not just to use in the active sense, but to exploit in the diplomatic sense. It has therefore weakened our position against both North Korea and Iran." He says that it has also "exacerbated the U.S. fiscal situation, which obviously has all sorts of economic repercussions."

"For all that, a lot of the impact on U.S. foreign policy still awaits how things turn out," Haass says. "It's a very different impact if Iraq suddenly implodes or becomes the venue for not just a civil war but a regional war. Obviously, in such a circumstance, the implications for U.S. foreign policy would be both greater and more negative."

In your book, The Opportunity: America's Moment to Alter History's Course, and in some op-ed articles, you've indicated you thought the war against Iraq in 2003 was ill-advised, and yet, you are also wary that a complete collapse in Iraq would have very negative repercussions. Overall, what do you think the Iraq war has done to American foreign policy?

Well first off, there's no necessary inconsistency between believing the war was ill-advised and being concerned about a collapse at this point. As many people have correctly pointed out, we are where we are. There's time to debate the wisdom of the war now, on the third anniversary, and there will also be time on future anniversaries.

In terms of the impact of the war on American foreign policy, I'm going to say two things. One is that it's too soon to do a complete accounting. Obviously, history's judgment is going to depend, in large part, on how certain things turn out in Iraq and beyond. But if you're asking me the impact up to this point, I would say that, on balance, it's clearly negative. It has absorbed a tremendous amount of U.S. military capacity, the result being that the United States has far less spare or available capacity, not just to use in the active sense, but to exploit in the diplomatic sense. It has therefore weakened our position against both North Korea and Iran.

Secondly, economically, it has clearly exacerbated the U.S. fiscal situation, which obviously has all sorts of economic repercussions. Diplomatically, this war has contributed to the world's alienation from the United States. I believe it's made it somewhat more difficult for the United States to galvanize its national interest or galvanize international partners in dealing with problems related to weapons of mass destruction. Clearly, U.S. credibility has taken a hit in that area.

For all that, a lot of the impact on U.S. foreign policy still awaits how things turn out. It's a very different impact if Iraq suddenly implodes or becomes the venue for not just a civil war but a regional war. Obviously, in such a circumstance, the implications for U.S. foreign policy would be both greater and more negative.

Do you think Iraq has a chance of becoming more like Afghanistan? I think you alluded to that once in an article saying that would be the worst-case scenario.

Right now I think that would be the best-case scenario. Let me just hasten to explain: If we had an Iraq that looked like Afghanistan looks—a relatively weak central government focused in on the capital and able to maintain order in the capital, and a country consisting of what you might call powerful regional leaders where a degree of economic rebuilding was taking place—that sounds pretty good. That is not to minimize in any way the challenges facing Afghanistan. There's still a continuing terrorist problem, there's still the continuing Taliban opposition, there's obviously the drug problem. But all things being equal, I wish Iraq's problems were of a similar scale. Unfortunately, they are far greater.

What do you think the worst case could be?

Well, the worst case for Iraq itself I would think is, in some ways, analogous to Lebanon two decades ago, where essentially you had a civil war exacerbated by the actions of its neighbors. An Iraqi civil war, by the way, would not just be between or among blocs of Kurds or Shiites or Sunnis, but within those groups. One could imagine civil wars particularly within the Shiites. It would be a civil war in which regional and external involvement was pronounced. You would have direct and indirect involvement: arms, money, personnel; so-called volunteers and possibly more, from Iran, from Saudi Arabia, possibly from Turkey and Syria. That, to me, is the worst-possible situation, because it would turn Iraq into a totally ungovernable area. You would have an enormous humanitarian crisis; you'd have negligible energy output. But worse, the spillover would be great. The potential for it turning into a larger regional conflict obviously would be huge. On top of it all, it would have the potential to poison relations throughout the region between Sunni and Shiite segments of society. So it could have a kind of copycat effect around the region.

Exacerbating that, or adding to it, would be what it would mean for the United States. Beyond the direct consequences of what I've just described, the fact that the United States would have by then invested—in every sense of the word—so much in Iraq and have so little positive to show for it would clearly energize forces and movements who are opposed to us. And it would raise large questions of doubt and confidence with those who are inclined to work with us.

Now in your book, of course, you do say it's very important for the United States to see Iraq through to the end, to avoid those problems. Do you have a sense that the American political support is deteriorating rapidly on this one? Or is this just temporary? If Iraq gets a government, will things improve?

A lot depends upon the scenario. If the scenario is what it's mostly been over the last couple of years until recently—where the principal challenge strengthening Iraqi security forces to deal with an internal challenge, the standing-up of a government that enjoys broad political support, and getting a constitution in place that enjoys broad public support—the American people will support this or any other administration, so long as there's a sense this strategy will gradually, over time, make progress, that the arrows are pointing in the right direction. I believe late last year, the administration, with the president's speech at the Council, regained some control over the domestic debate. The votes against Congressman John Murtha [(D-PA) who called for an early withdrawal from Iraq] and others, I believe, were proof of that.

Where I believe the administration stands a chance of losing the American public and the Congress, essentially having the bottom fall out, is if the principal dynamic in Iraq becomes one of civil war—of major, not minor, sectarian clashes—at which point, the security forces themselves dissolve along sectarian lines [and] there's essentially no longer a meaningful government to have as a partner, in which literally and figuratively the bullets start coming from any and every direction. We're not there yet, but we've seen some glimpses, we've seen some harbingers of it, in the aftermath of the terrorist attack on the Shiite Imam Ali al-Hadi holy shrine in Samarra, for example. If that were to come to pass, it's quite possible that not simply the American people, but people in the U.S. military and elsewhere will say, "This is not a situation in which the United States can play a useful role." It's simply, to use a financial metaphor, throwing good money after bad. If we reach that point, the administration will have no option but to think about trying to get out and limiting the damage.

What did you think about that report coming out in Foreign Affairs about the intelligence malfunctioning before the war, which led people like then-Secretary of State Colin Powell to go to the Security Council with very faulty information?

I had two reactions to the article, which is fascinating. One is about Iraq. The only word that keeps coming to mind is ironic. Here was Saddam Hussein's regime that was fundamentally founded on fear and on tyranny. But ironically enough, the same fear that in some ways was the foundation of the regime became its undoing. Good information never could make its way up the ladder. People were so afraid of telling the truth—to put it bluntly, the phrase "shoot the messenger" was not simply a saying in Iraq, it was the real thing—that ultimately, the fear that was the glue of the regime became its undoing. So there's a sense of irony, and maybe also a sense of just desserts.

Secondly, on intelligence: Iraq underscores the significance of what you might call a mindset. If you have certain assumptions, everything that comes at you in the way of information you will tend to slot into those assumptions. Everybody assumed Saddam had chemical and biological weapons. So when evidence arrived that, for example, there had been some physical activity at sites believed or known to have once been places where chemical or biological weapons were, everyone assumed this was somehow part of concealment. It wasn't until I read the article that I saw these were Iraqi efforts, in some cases, to make sure there were no remaining illegal weapons of mass destruction. It's a powerful reminder of how assumptions and mindset can totally frame the way information is perceived. To me, it's a powerful lesson of the need to constantly question first-order assumptions; to ask yourself, How else could this information be explained?

Another example, which is when Saddam would not give a complete accounting of all the material he had imported and all the material he had destroyed—again, virtually everyone jumped to the conclusion that he was still hiding something. It turned out, reading this article in Foreign Affairs, that his principal motive was not to allow people inside Iraq or inside the region to know that he had no weapons of mass destruction. From Saddam's point of view, that would have been a devastating admission of weakness. So again, assumptions are potentially dangerous things if you allow them to dictate how information is perceived.