Secratery of Defence, Robert Gates, is going on a surprise visit to Afghanistan. Mahmoud Ahmadinejad also happens to be going to Kabul, overlapping with the Gates visit. It’s possible they will just drive past each other in Kabul. But it seems more likely that they are going to finalize some sort of agreement that’s been bubbling up behind the scenes. Possibly the Afghan government, which wants good relations with both Iran and the US, will try to broker an agreement.