How many people would die in an Iraqi War?
A central question about the war in Iraq is the likely cost in terms of casualties. Many Americans who would support an invasion on the assumption of 250 dead might feel very differently if our losses numbered 10 times as many. Unfortunately, such predictions have proven notoriously inaccurate in the past. On the eve of Operation Desert Storm, several military experts forecast U.S. losses in the range of several thousand, and the Pentagon expected even higher numbers killed. Actual American losses were just under 400 (of whom about 150 were killed by direct enemy action, the others being lost in accidents or friendly-fire episodes).
Is it possible to make better predictions this time around? It may be, but not with a single number or narrow range. Based on available methodologies, the likely numbers of U.S. military personnel killed in a future war to overthrow Saddam Hussein could plausibly range anywhere from roughly 100, in the event of little fighting, to 5,000, in the event of intense if relatively short urban combat, with total numbers of wounded about three to four times as great either way. Even as broad a range as this is based on certain assumptions. Iraqi troop losses might be expected to be anywhere from 2,000 to 50,000, with civilian casualties in the same relative range. Narrowing the 100-to-5,000 range further depends on more detailed assumptions about what kind of war we're likely to fight, and most of all on how hard the Iraqis would fight.
Operation Desert Storm and, more recently, Operation Enduring Freedom in Afghanistan probably don't provide much insight into the likely nature of a future war in Iraq. Saddam seems unlikely to place many of his forces in the open in a future war. Because Iraq knows its weaknesses against the U.S. military in open settings, and because it is Saddam Hussein's regime and weapons-of-mass-destruction capabilities that would be at issue in a future war, one has to assume that the combat would be primarily urban.
This assumption immediately changes the calculus about a future war, moving it away from a comparison with Desert Storm. Airpower would be much more difficult to employ against Iraqi forces that could intersperse themselves with civilian vehicles and populations. This type of tactic was employed near Basra during Desert Storm and has been used in the subsequent 11 years. Iraqis have sought to place valued military assets near civilian populations to make it harder for the United States to bomb them. Iraqi forces have much better cover within cities, or even forested regions, than in open desert. Recall that even after eight years of further modernization after Desert Storm, NATO airpower was of quite limited effectiveness against small groups of Serb forces operating within forests, towns, and civilian populations in the Kosovo war. If U.S.-led forces tried to fly low to find enemy forces against this complex backdrop, they would have to contend with an Iraqi air-defense network consisting of, among other things, some 6,000 air-defense guns and 1,500 surface-to-air missile launchers (including man-portable SAMs).
Nothing about new technology and new war-fighting concepts associated with the so-called revolution in military affairs seems likely to radically change the challenge of urban warfare anytime soon. For example, recent Marine Corps experiments incorporating such new concepts suggested that U.S. troops could still suffer quite high casualties in urban combat.
What do past cases tell us about how a future war conducted largely in the streets of Baghdad might play out? As this sidebar explains, two useful parallels are the U.S. invasion of Panama in 1989 and the U.S. experience in Mogadishu, Somalia, in 1993. Iraqi forces are almost surely better armed and better trained than the military or paramilitary organizations we fought in those cases. Thankfully, they are probably also far less motivated.
That said, it is important to remember that the Iraqi Republican Guard forces, numbering about 100,000 troops, fought reasonably hard in Desert Storm. These troops enjoy a number of benefits from Saddam's regime—and are heavily implicated in his rule. Republican Guard forces would probably fear retribution from an alternative regime or from Western occupying forces more than they would fear Iraqi opposition forces and American airpower on the battlefield. How much they would fear American invasion forces, and thus when they would choose to surrender, is difficult to answer—as are such questions as whether they might be convinced to desert Saddam by some sort of amnesty offer. Yet another issue in estimating casualties is whether a threat to hold Iraqi commanders personally responsible for war crimes may deter the use of weapons of mass destruction.
Simply scaling the results of Panama for the size of the Iraqi military leads to an estimate of about 2,000 Americans killed, more than 10,000 dead Iraqi military personnel, and tens of thousands of dead Iraqi citizens. If, however, the only forces that fight hard are the elite—somewhat more than 100,000 Republican Guard, Special Republican Guard, and palace guard forces—extrapolation from the Panama case suggests that losses on all sides might be only one-fourth as great. Such an outcome is plausible. Indeed, U.S. war plans appear to envision targeting only these elite forces, at least at first, and trying to convince the regular conscript army to change sides or sit out the war.
The Somalia analogy is also worth considering. The firefight on the night of Oct. 3-4 can be used as a way to generate pessimistic estimates of how war in Baghdad might go. As noted, that operation involved about 160 Americans against a single objective, together with roughly a dozen ground vehicles, and more than a dozen helicopters. An operation in Baghdad might have to be 50 to 100 times as large if an initial assault attempted to secure key facilities. With comparable casualty rates, U.S. losses could number 1,000 or more just in this phase of the fighting.
One major wild card remains: the likely consequences of any Iraqi use of weapons of mass destruction. Consider first Scud attacks against Iraq's neighbors. Even if these missiles are equipped with chemical or biological agents, they seem a relatively minor threat. Saddam may have as many as two dozen Scuds left, but these weapons mostly missed their targets during the Gulf War and often broke up in flight. Iraq has not been able to test them to improve their performance since. Delivering a chemical or biological agent is best done at a steady altitude by an aircraft that spreads the agent over a large area, not by a rapidly descending ballistic missile that may disperse the agent too soon or too late—and in any case, probably in far too concentrated a dose in one place. Should that one place be a sports stadium or shopping mall, the result could be disastrous. But given the Scud's inaccuracy, that would require extreme luck on the part of Iraq.
Of course, Iraqi attacks against civilian populations in places like the United States could be serious, especially if they involved biological agents, in which case plausible casualties could reach into the hundreds or even the thousands. But Iraqi special forces have not focused on preparing for such attacks in the past; instead, they have reportedly been dedicated to efforts to acquire technologies for producing weapons of mass destruction. It is also unlikely that Iraq has access to the most dangerous pathogens, such as smallpox. On the other hand, Saddam may be willing to provide such agents to Hezbollah or al-Qaida operatives under certain circumstances. On balance, the risk that germ or chemical weapons will be used successfully may be relatively small—but it is also quite real.
Iraq could also increase casualty levels of U.S. or coalition forces by using WMD against them, particularly its thousands of chemical-filled artillery shells and rockets. But doing so would probably increase casualties by no more than 10 to 20 percent, given historical precedent in conflicts such as the Iran-Iraq war. U.S. forces are much better equipped to protect themselves from such attacks than most militaries have been in the past. Nonetheless, Iraq might gain some military advantage by using battlefield chemical weapons, if at a huge cost to its own civilian populations (and perhaps to its own troops, should winds shift). The use of chemical weapons could oblige coalition forces to fight in protective gear, slowing operations and generally complicating the mission. If the effects of fighting in such gear were comparable to those of fighting in bad weather or difficult terrain, the pace of fighting and the effectiveness of coalition forces might decline 25 to 50 percent, and casualties might rise by a comparable percentage.
The United States and coalition partners would win any future war to overthrow Saddam Hussein in a rapid and decisive fashion. This will not be another Vietnam or another Korea. But casualties could be significantly greater on all sides than in the 1991 Persian Gulf War. The best analogy for what such combat is likely to involve is not Desert Storm, but the 1989 U.S. invasion of Panama—and on a much larger scale. There is a very real possibility that American deaths could exceed 1,000 in number, and several thousand deaths cannot be ruled out. To count on easy victory, as many American proponents of war seem to do, is not only unsupported by the available evidence and by the methodologies of combat prediction. It's also an irresponsible basis on which to plan military strategy in any future war against Saddam Hussein.
Michael O'Hanlon is a senior fellow at the Brookings Institution.
Photograph on Slate's home page of U.S. military personnel by Sukree Sukplang/Reuters.