The rising threat of a sectarian civil war appears to be helping to avert one. Saudi Arabia, Kuwait, and some other nations bordering Iraq are increasing measures to curb extremist support in Iraq, and are curbing assistance to groups responsible for actions that are feeding sectarian tensions. Apparently leaders in these countries have decided that an Iraqi civil war along sectarian lines will inevitably spill over onto their soil, as large numbers of refugees flee the fighting, while their own citizens become radicalized in support of co-religionists in Iraq, both events possibly fueling internal disorders.
In theory, these governments should welcome instability in Iraq that could topple the Iraqi government and restore the Sunnis. Indeed, in the aftermath of Saddam's fall these states didn't do much to support the new government and allowed elements to undermine the Shias and Kurds as they established themselves. But now they see the existing Shia/Kurd-dominated government as acceptable and preferable--a source of stability. This is surely progress, I should say, and an admission that we are succeeding in our Iraq project.
So when do the so-called realists over here accept the new status quo as the stability they crave?
