"You have a lot of suspicion from the neighbors of Afghanistan about U.S. intentions. Iran is already, to some extent, trying to undermine the U.S. in Afghanistan. Russia is now becoming increasingly nervous about a more permanent U.S. presence in Central Asia. And China is not keen that the U.S. should be so close to its borders over a long period of time. Certainly, if the U.S. is going to be there for a long time, it's going to exacerbate regional tensions."