With the focus of U.S. military efforts in the middle east shifting from a tentative success in Iraq to an uncertain outcome in Afghanistan, it may be worthwhile to compare the two situations.
In Iraq, the U.S. had a long term plan of establishing a government that would represent all Iraqis. In Afghanistan, the goal appears to be retribution against a single person, with the U.S. commitment to the welfare of the populace far from clear.
Iraq's primary export was expected to be oil, which we're happy to buy. Afghanistan's biggest export is opium, comprising a third of the country's economy, an export that the U.S. government wishes to shut down.
"We do deserts, we don't do mountains." Deserts and flat terrain like Iraq are ideal for large, organized armies. Mountains favor insurgents.
Afghanistan may be shaping up to be more like Vietnam than like Iraq. Our key mistake in Vietnam was the commitment of ever increasing numbers of ground troops. Repeating that mistake may not be the best idea.
I thought our key mistake was trying to win the hearts and minds of subsistence farmers who did not give a crap what kind of government they had, as long as people would stop napalming their rice.
Parallels with the crops aside, based on what I've read, the people of Afghanistan would much rather have a different government.