When General David Petraeus and Ambassador Ryan Crocker testify before Congress this week, much of the discussion will focus on population security. Civilian casualty rates, in particular, are a very important measure of success in Iraq. Though some critics of U.S. Iraq strategy focus on rates of sectarian violence, broader measures present a better picture of the situation in Iraq. These broader measures show that the "surge" has been a success in reducing civilian casualties and improving overall security in Iraq.

From July 2006 to August 2007, I was charged with looking at various measures of population security and analyzing the trends for the U.S. Ambassador and other senior officials at the Baghdad Embassy on a weekly basis.

In recent days, the media have been keenly interested in population security measures, with a number of articles being written in advance of this week's hearings.[1] Naturally, there will continue to be a great deal of discussion regarding population security during this week's hearings. In order to cut through the clutter, policymakers and the public at large should focus on the following three issues:

1. The "surge" has been especially effective in reducing civilian casualties in Baghdad, although less so in the rest of Iraq. Because the surge has focused primarily on security in Baghdad and the "belts" on the periphery of the city, security has improved in those areas, as measured by total civilian casualties. This was seen especially in the past several weeks and has been widely reported in major news outlets.In response, insurgents are now moving from Baghdad to more permissive areas to commit acts of violence. Recent high profile attacks, such as the mid-August attacks on the Yezidi communities in the Ninewa province and the July attacks in Amerli in the Salah ad Din province, show that insurgents are seeking out softer targets to perpetrate violence.
   
   
2. Sectarian casualties are only a fraction of total civilian casualties, and such numbers lack meaning in ethnically or religiously homogeneous communities. The military defines sectarian attacks as violent acts by one ethnic or religious group against another or violent acts perceived to have been targeted in that way. What is important is the cross-ethnic dimension of this definition. Shia-on-Shia or Sunni-on-Sunni violence would not likely be considered sectarian in nature because the violence does not cross from Sunni-to-Shia or vice versa. Therefore, sectarian violence metrics only have meaning in mixed areas.
   
   To put this into perspective, consider sectarian violence in the western Iraq province of Anbar over the past 18 months. By this measure, one would have to conclude that Anbar is one of the safest provinces in Iraq. Clearly this is not the case, as the cities of Ramadi and Fallujah were historically insurgent hot spots. There has been very little sectarian violence in Anbar because the province is overwhelmingly (95 percent or more) Sunni. Therefore, broader measures (e.g., total civilian casualties by violent means) are needed to understand insights on population security.
   
   The Government Accountability Office (GAO) recently criticized sectarian violence measures, noting that "[M]easuring such violence requires understanding the perpetrator's intent, which may not be known."While the GAO uses this contention to argue that it is unknown whether sectarian violence has decreased (actually, sectarian violence probably has decreased), the basic criticism of the categorization of sectarian violence has some validity. In particular, sectarian violence measures miss between 35 percent and 65 percent of civilian casualties on a month-to-month basis. It is not unreasonable to assume that, between May and August of this year, total civilian casualties have been twice as high as the sectarian civilian casualty rates reported by the military.
   
   
3. Violence statistics collected by the military should be viewed as a lower-bound estimate because they tend to miss smaller incidents. Coalition Forces (CF) respond to major security incidents, such as roadside and vehicle bombs, mortar and rocket attacks, and major small arms attacks by insurgents. They have good systems in place for tracking and estimating casualties from these events. CF are less likely to respond to smaller incidents, especially murders and executions. When murdered bodies are found, they tend to be reported to Iraqi authorities, not to CF. Therefore, CF estimates will necessarily understate total civilian casualties.
   
   In addition, over the past several months, the military has reduced its presence in a number of provinces where security has been transitioned to the Iraqis. This process-called "Provincial Iraqi Control," or "PIC"-has now occurred in seven provinces: the three Kurdish provinces of Dahuk, Irbil, and Sulaymaniyah in the north and the southern areas of Najaf, Maysan, Dhi Qar, and Muthanna. When provinces complete the PIC process, U.S. and Coalition military forces rarely leave their Forward Operating Bases (FOBs), unless they are requested by the provinces to aid local security forces. Consequently, CF will record fewer security incidents in these areas over time.

   To its credit, the military has been increasingly using Iraqi sources to supplement its own analyses; if this continues, CF casualty estimates should improve over time. Currently, however, casualty estimates from the military should be viewed as a lower-bound.

Conclusion
Policymakers and the public should focus on how the surge has improved population security in Iraq, defined broadly. Focusing only on sectarian violence misses 35 percent to 65 percent of civilian casualties nationwide and nearly all the violence in homogeneous areas of Iraq. When a broad measure of population security is used, total civilian casualties have dropped by about 20 percent between January and August 2007. Whether or not this nationwide reduction in violence will allow needed political progress in Iraq is still an open question.

Kirk A. Johnson, Ph.D., is a Visiting Fellow at The Heritage Foundation and served as Deputy Director for Assessments in the Joint Strategic Planning and Assessment office at the U.S. Embassy in Baghdad in 2006-2007.