Even assuming Muslim rage doesn't produce a worst-case scenario—say, regime change in Pakistan that puts nuclear arms in the hands of terrorists—there is still plenty to worry about, most notably the next generation of anti-American terrorism quietly incubating in the hearts and minds of adolescent Al Jazeera watchers around the world. Further, anti-American Muslims—already trickling into Iraq from Jordan—could start showing up in larger numbers, including the occasional suicide bomber (who will make American troops even more jittery, leading to more dead Iraqi civilians for Al Jazeera to highlight, and so on). Every week that this war drags on is a week in which bad things can happen, and Rumsfeld's seeming indifference to this fact does not inspire confidence. (According to Marshall's Washington Monthly piece, the zanier neocons may actually welcome growing Muslim hatred of the United States as somehow advancing their grand design—a reductio ad absurdum if there ever was one.)
Of course, the administration may yet proceed with a fairly prompt move on Baghdad—i.e., without waiting for the 4th Infantry Division to arrive in mid-April. But approaching Baghdad with less than overwhelming force will probably mean more civilian casualties. The fewer ground troops we have, the more bombs we use; and the more precarious a soldier's position, the less picky he'll be about whom he shoots. So, the total amount of bad American karma pumped into the Muslim world will still be higher than it would have been if Rumsfeld had listened to his generals and put more troops on the ground to begin with. (For details on how we wound up in this predicament, read Slate's Fred Kaplan on a) how the pre-invasion war games may have been rigged; and b) the "transformational" military doctrine that has enamored some in the Pentagon.)
And now for a shocking admission: I, too, thought the war would be relatively quick. I predicted in this magazine that within two weeks of the war's first shot, loyalty to Saddam would start to crumble—a prediction that has about 48 hours before the life drains out of it. But that was the optimistic note in a fundamentally pessimistic assessment. I was arguing that this war—without U.N. authorization, and without U.N. inspectors having found a smoking gun—was on balance a mistake even if it went quickly, given the long-term blowback. In contrast, Wolfowitz and Perle championed a grand strategic vision that features an intricate series of rosy scenarios. So, the past week's evidence that they're prone to wishful thinking casts doubt on their whole argument.
In retrospect, there were good reasons to doubt that this war would go as smoothly as other American wars of the past 13 years. For example: Unlike them, this is a war in which we both a) are fighting people in their homeland, not just kicking them out of someone else's; and b) have no major, organized indigenous ground force to help us do the dirty work. But, once the geopolitics of the situation had convinced me that any essentially unilateral war would be a mistake, I didn't reflect long and hard on exactly how messy (and thus exactly how bad an idea) such a war would be.
Also, I made the mistake of putting some trust in talking heads—all those can-do TV military analysts, and even people like Wolfowitz and Perle. I had always assumed that the administration's hawks do understand war, even if they don't understand geopolitics. Turns out I was only half right.