4 December issue of the Weekly Standard - We Can Put More Forces in Iraq - and they Would Make a Difference by Frederick Kagan.

Many months into the debate over finding a new strategy in Iraq, two myths continue to cloud the discussion. The Washington Post recently proclaimed: "The United States and its allies in Iraq would need at least 500,000 and perhaps more than 1 million troops" to bring order to the country. Incoming House majority leader Steny Hoyer declared: "As a practical matter, there are no troops to increase with." Neither of these statements is true. The persistence of these myths forecloses serious consideration of the only option likely to bring peace to Iraq.

Relevant historical examples do not support the notion that hundreds of thousands more troops are needed to improve security in Iraq. A study of post-conflict operations in the Balkans, Afghanistan, and elsewhere conducted by Ambassador James Dobbins showed that success in those operations--characterized by severe ethnic and sectarian violence--required force ratios of 1 soldier per 100 inhabitants. Iraq poses challenges that are in some respects more severe, at the moment, but it also offers its own rules-of-thumb. Successful clear-and-hold operations in Tal Afar required a force ratio of around 1 soldier (counting both U.S. and Iraqi troops) for every 40 inhabitants. On the other hand, in 2004 Major General Peter Chiarelli suppressed a widespread uprising in Sadr City (an area inhabited by about 2.5 million Shiites) with fewer than 20,000 U.S. soldiers--a ratio of about 1 to 125.

Then there's the question of the size of the population to be pacified. Most of Iraq is relatively calm. Instances of violence in the Kurdish north and the Shia south are rare. No responsible analyst advocates sending large numbers of troops into either area--they are not needed and would not be welcomed. Disarming the Shia militias is a process that must be undertaken only after the Sunni Arab insurgency is under control, and it cannot be undertaken primarily by American forces directly confronting the Shiite population. Using all of Iraq's 27 million people as a baseline for estimating force ratios is, therefore, an invalid approach.

The U.S. command repeatedly and correctly points out that about 80 percent of the violence in Iraq occurs within a 35-mile radius of Baghdad, among a population of perhaps 10 million. Baghdad itself has roughly 6.5 million inhabitants, including the 2.5 million Shiites in Sadr City. These figures provide the basis for a more realistic estimate of the force levels needed. Applying the high-end ratio used in Tal Afar over the entire metropolitan Baghdad area would generate a requirement of 250,000 troops--both U.S. and Iraqi. There are currently about 100,000 Iraqi army troops that the U.S. command considers trained and ready. There are almost 150,000 American troops in Iraq now, including perhaps 70,000 combat troops. Conducting Tal Afar-type operations across the entire capital region all at once would require concentrating all available forces in the area and a "surge" of about 80,000 U.S. soldiers--a large number, to be sure, but very far from the "hundreds of thousands" or even "millions" generated by the use of specious historical examples.

But the situation is not even this dire. Not all areas of the capital region require such an intensive deployment. Indeed, previous successful operations even in Baghdad did not require such high force ratios. What's more, skillful military planners conduct operations in phases, and that is exactly how this one should be prepared and executed. The recent unsuccessful effort to secure Baghdad, Operation Together Forward II, was broken into a series of phases. U.S. and Iraqi troops working together succeeded in clearing the neighborhoods they entered one after the other. But that is not why the operation failed. The problem, according to much anecdotal evidence and the recent testimony of the director of the Defense Intelligence Agency, General Michael D. Maples, is that the U.S. military command did not leave American forces behind in the areas that had been cleared. That mistake allowed insurgents to reinfiltrate those neighborhoods and begin the cycle of violence again.

There is every reason to believe that a reformulated operation, proceeding in phases to clear Baghdad neighborhood by neighborhood, but with sufficient force levels to leave significant American troops behind in the cleared areas, would be much more successful...
Much more at the link...