Actually the Afghan transitional government is protected by Afghans, Americans, and other allies
not just American soldiers. About 40 or 50 American specialists are training Afghan soldiers for the specific job of protecting Karzai and other top Afghan leaders. This is especially important in light of recent assassinations and attempted terrorists acts by remaining Taliban/Al Queda savages.
You may not have the capacity to appreciate much the new Afghan transitional government, but it's a pretty good start for a better Afghan future.
Have you ever seen a better Afghan government?? Please name it.