Now, as the main battle in Iraq moves toward a conclusion near or in Baghdad, the specter that concerned Secretary of Defense Rumsfeld and his generals before the war - a bloody fight between US troops and the remnants of the Iraqi forces inside an urban battlefield - emerges more prominently.
It is a scary prospect to US military professionals, who pride themselves, rightfully, on never again having to engage in a "fair fight" in which an enemy's capabilities will match theirs. And to an American public that expects and demands low friendly casualties and minimal collateral damage.
But it may not be as scary as military pundits proclaim. Let's be clear: Urban conflict, as the US military refers to combat operations in relatively built-up and populated arenas, has always been dangerous, destructive, and bloody. The battles for Stalingrad, Berlin, and Manila during World War II, for Hue in Vietnam, and in Mogadishu were the deadliest of the conflicts in which they occurred.
It would be ridiculous to dismiss the concern with urban conflict as overblown. But if you balance reasons urban conflict is a "worst case" against what the US military would have going for it, the historical precedents have less bearing.
Concern with urban conflict stems from the terrain there. It is highly complex and, as military trainers say, "very three-dimensional." Upper stories of buildings may be enemy observation and sniper posts. Sewers may be enemy communications tunnels and ambush bunkers. Buildings block sight and line-of-sight communications, laser designators, and direct-fire weapons. It is a terrain of tunnels, bunkers, twists, and turns.
Some believe the Iraqis' street smarts give them the edge. Interestingly, that is where the military pundits could be wrong. Cities like Baghdad are fundamentally human - not natural - artifacts. As such, there is more information about a given city block of Baghdad than for almost any other similar-sized area of nonurban terrain. The locations of buildings, sewers, and telephone lines that have made urban terrain so formidable are recorded in blueprints, maps, maintenance records, photographs, directories, and scale models. And the US Geographical Information Systems that combine traditional location information of recorded plans with up-to-date, highly precise radar-generated digital terrain-elevation data and other measurements have grown dramatically over the past decade.
Combining it into something intelligible is terribly difficult. Getting it in usable form to those who may use it is challenging.
But the US Department of Defense has done all this. The reason cities have been so militarily formidable has been that it has been so hard to know where things are. In the absence of knowing where things are - and are not - it's difficult to know where people in the city are and are not. In a battle, the side that knows the most about where things are has a huge advantage - particularly if that knowledge is comprehensive. That's because of the other characteristic of this human artifact - the fact that cities are systems. The buildings, streets, sewers, water lines, gas lines, telephone lines, and electricity lines - all the things that distinguish a city - are all tied together. And that means with comprehensive knowledge of a city, you can influence, if not control, almost anything that occurs within a local part of that city.
That's what offsets the street smarts of someone who has intimate knowledge of a room, building, or neighborhood. If the last battle is in Baghdad, the US will enter it knowing more about the terrain than the Iraqis do.
The significance of that kind of knowledge, of course, depends on being able to use it. And the US military has the ability to take advantage of its knowledge edge with precision and speed. The US clearly possesses the ability to destroy Baghdad. But it won't, for both strategic and moral reasons - and because it has other means of coping through new capabilities:
• An unprecedented knowledge of the urban terrain in Iraq (that is intelligible, transmittable to its forces, and readily useable by them).
• An unprecedented understanding of the systemic character of the urban terrain in Iraq - including precise knowledge about the location of all the potential choke points and nodes in those systems.
• An unprecedented capacity to apply violence with precision and speed where it will have the greatest effect.
None of this makes the prospect of a fight in Baghdad anything other than a worst case. And it doesn't change the potential of such a fight to be very ugly. But it does, perhaps, alter presumptions some Iraqi military leaders may have.
If the conflict goes into Baghdad, it still won't be a "fair fight." If remnants of the Iraqi military try to make a last stand there, they will lose and possibly die - but they won't take many Americans with them.
• James Blaker, an employee of a defense consulting firm, served as a deputy assistant secretary of Defense and deputy undersecretary of the Air Force in the Reagan administration, and as the senior adviser to the vice chairman of the Joint Chiefs of Staff in the Clinton administration.