Today saw the deadliest attack on US troops in over a year--and violence overall, at least spectacular al-Qaeda style car bombings, seems to be on the rise. Barack Obama probably can't "win" Afghanistan without withdrawing from Iraq more or less on schedule, something he insists he's going to do. But I just find it hard to envision US troops leaving en mass if Iraq starts plunging back into chaos. Asked whether an "insurgent surge" is underway the US commander in Iraq, Ray Odierno, says no. But who knows what's to come? It's an incredibly ugly choice we need to hope Obama won't be confronted with.

An Iraqi soldier stands guard inside the operation room of the Abu Ghraib power plant on the outskirts of Baghdad on April 8, 2009. (Photo: Ahmad al-Rubaye/AFP/Getty Images)

--Michael Crowley