Danielle Pletka, vice president for foreign and defense policy studies

Since the return of Gen. David Petraeus to Iraq, much has gone right. American troops have wrought wonders fighting alongside former adversaries in Anbar Province and Baghdad. Our trust, however, can go too far.

A more jaundiced eye would go a long way in ensuring American security and Iraq's long-term stability. General Petraeus has complimented our new friends among former Sunni rejectionists, a group known as the Sons of Iraq or the Awakening, saying they "have come to accept, we believe, that they are not going to run Iraq again." Likewise, other American military leaders are increasingly optimistic that Fadhila, a Shiite party that dominates the provincial council in Basra, may have turned against its sponsor Iran and decided its future lies in supporting American goals.

No doubt both Al Qaeda and Iran overplayed their hands and alienated Iraqis. At the same time, the surge convinced both Sunni and Shiite rejectionists that United States forces would remain the strongest in Iraq for the time being. American leaders need to recognize, however, that power calculations, not principle, have driven these conversions.

No, we should not shun friends where we find them, even fair-weather friends. Nor is it right, as some Democrats have suggested, that our Iraqi allies are merely mercenaries. But Americans must understand that we will need to maintain an imposing presence in Iraq for a long time to come, ensuring that all sides have enough of a stake in the new order so that violence loses its appeal.

Danielle Pletka is the vice president for foreign and defense policy studies at AEI.