WASHINGTON — The Obama administration's decision to withdraw the bulk of U.S. troops from Iraq over the next 19 months has sparked fears that Iraq will once again plunge into the wide-scale and debilitating violence that it endured from 2004 to 2007. Those fears are, for the most part, overblown. There are good reasons to believe that the level of stability achieved in Iraq can be maintained even without a large-scale U.S. presence.

To understand why, it is important to know what else was going on inside Iraq in 2007, when U.S. President George W. Bush ordered the "surge" of 20,000 additional troops and Gen. David Petraeus shifted U.S. forces to a more aggressive strategy. For, although the surge was important, two other factors played a critical role in bringing Iraq back from the brink.

First, Baghdad had been transformed into a Shiite-dominated city. Although exact statistics are hard to come by, in 2003 approximately 35 percent of Baghdad's population was Sunni. Today, based upon the results of the recently held regional election, Baghdad is only 10 percent to 15 percent Sunni. This means that between 1 million and 1.5 million Sunnis have fled the capital. Most now are refugees in Jordan and Syria, and they are unlikely to be welcomed home anytime soon by the new Shiite elite running the country.