That is especially true of a war like the one in Iraq. Consider these data: Between November 2004 and February 2005, according to the Brookings Institution's Iraq Index, the number of coalition soldiers in Iraq rose by 18,000. In that time, the number of Iraqi civilians killed fell by two-thirds, and the number of American troops wounded fell by three-fourths. The soldiers were soon pulled out; by the summer of 2005, American and Iraqi casualties rose again. Later that year, the same thing happened again. Between September and November of 2005, another 23,000 soldiers were deployed in Iraq; once again, both Iraqi and American casualties fell. In the early months of 2006, the number of soldiers fell again, and casualties spiraled up.
The picture is clear: More soldiers mean less violence, hence fewer casualties. The larger the manpower investment in the war, the smaller the war's cost, to Iraqis and Americans alike. Iraq is not an unwinnable war: Rather, as the data just cited show, it is a war we have chosen not to win. And the difference between success and failure is not 300,000 more soldiers, as some would have it. One-tenth that number would make a large difference, and has done so in the past. One-sixth would likely prove decisive.
Counterinsurgency warfare is more about protecting than killing--like a nationwide exercise in community policing. And the lesson of the 1990s in American cities is that the best way to reduce the level of criminal violence is to put more cops on the street. The lesson of the past three years in Iraq is the same: If the goal is to cut our losses, the best move is not to pull back, but to dive in--flood the zone, put as many boots as possible on the most violent ground. Do that, and before long, the ground in question will be a good deal less violent.
War is not poker; the stakes in Iraq are much higher than a little money or a few chips. But war's psychology bears some resemblance to a well-played game of cards. The only way Americans lose this war is to fold. That seems likely to be the next move, but it is the last thing we should do. Far better to call and raise. Our cards are better than theirs, if only we have the nerve to play them.
William J. Stuntz is the Henry J. Friendly professor at Harvard Law School.