I always hated when important people came to visit us. Cheney came while I was in Iraq and it was a giant pain in the ass. If you want to meet the troops, video conference them. They don't need or want the distraction you bring. I guarantee you there isn't a troop in Afghanistan sitting there thinking "I wish my Congressman were here." They aren't going there to visit the troops, they are going there for pictures.
Ceterum censeo Carthaginem esse delendam