The Iraqi people will gain their freedom as a result of this war, but the American people will lose some of theirs. Whatever comes next for Iraq—foreign occupation, economic sacrifice, political chaos, ethnic and religious tensions—will be better than what came before. (Saddam has killed an average of fifty Iraqis a day since he seized power in 1979.) But with every bomb that falls on Baghdad, the question of what comes next for America invites a darker answer.

For some unlucky American soldiers the battle of Baghdad may come next—a battle for which the Pentagon has not provided the necessary punch, according to an analysis by two British defense experts published last week in The Financial Times. "Historical precedent," they write, "suggests that a minimum of nine attackers to each defender—if that defender is determined—represents a realistic planning figure" for urban warfare. Their (high) estimate of the forces available to Saddam is 100,000. To attack them the coalition has only around 20,000 infantrymen, the British authors say, not the hundreds of thousands that history argues are required. War planners say technology has dispensed with the need for such numbers, but urban warfare, we have heard again and again, negates many of the advantages of technology. Even if technology has cut the old ratios in half, that still leaves coalition forces far short of the optimum. If the British analysts are correct about the gap between the numbers of infantrymen available and the number required to overwhelm the enemy and end the fighting rapidly, before U.S. and civilian casualties mount, then this is the most frightening example yet of how Pentagon planners, counting on shock and awe bombardment to collapse the regime, did not plan for the war Saddam has forced upon them.

The Iraqis reportedly have studied what happened in Jenin, the small West Bank city that the Israelis, trying to root out Palestinian gunmen, besieged last spring. Their technological superiority was of little avail on a battlefield of narrow streets lined by low-roofed buildings, and the Israelis ran a gauntlet of ambushes, snipers, and booby traps. Twenty-three Israeli troops were killed in a week of street fighting against a handful of guerrillas in a town a fraction the size of Baghdad. Twenty-three dead is to Israel what 500 dead is to the U.S.

Israeli casualties were so high in Jenin for a reason that applies to U.S. forces in Baghdad: fearing the outcry a "bloodbath" would provoke, the Israelis put their soldiers at risk to avoid civilian casualties. In the event, the Israelis killed fifty-two Palestinians, about half of them civilians—awful enough, but no bloodbath. Yet the Israelis were blamed for perpetrating one. Jenin was a huge propaganda defeat for Israel as Baghdad will be for the United States. Israel can endure regional odium. It does not depend on the cooperation of Arab regimes to prosecute its war on terrorism; the U.S. does. With anti-U.S. passion roiling the Arab "street"—even before the war in Iraq 97 percent of Saudis had an unfavorable opinion of the U.S.—the regimes will be under popular pressure to scale back their level of cooperation, which has been vital to U.S. efforts to roll up al Qaeda. Syria, notably, has shared intelligence that helped lead to the apprehension of suspected al Qaeda members in Germany and Spain. Now the U.S. is issuing threats to Syria to stop its alleged assistance to Saddam, sacrificing the war on terror for the war in Iraq.

"Bin Laden must be laughing in either his grave or his cave," Fawaz Gerges writes in the Los Angeles Times. After September 11, bin Laden summoned Muslims to a jihad against the United States, but "leading Muslim clerics cautioned young men not to be swayed" by his call "and said that only legitimate institutions and accredited scholars should be heeded." Now these same clerics have issued "fatwas" against the "new crusaders" for attacking Iraq. "The United States," Gerges concludes, "has alienated those in the Islamic community who were its best hope."

Perhaps a benign (and brief) U.S. occupation of Iraq can abate the fury building across the Muslim world. But don't count on it. The suicide car-bombing of U.S. Marines over the weekend—and the resulting orders issued to U.S. forces to fire on vehicles that do not stop at their command—previews a tragic occupation. It will not take many mistakenly shot-up civilian vehicles to give bin Ladenism a life beyond bin Laden. This war, Egyptian president Hosni Mubarak said yesterday, may create "a hundred bin Ladens."

So the terrorists will be coming after us throughout our lives: the U.S. intervention in the Middle East that bin Laden hoped for will provide the jihadis with fresh fuel for their propaganda. And with each attack freedom will give way before the imperatives of security. Thus Mr. Bush's crusade to liberate Iraq may fasten authoritarian government onto America. Our children will inherit a country of fear.