They are defending corporate and imperial interests in Afghanistan, which is the real reason why troops are sent overseas...and always has been. Not for freedom. Not for justice. Not for defence. For business reasons and protecting imperial interests. Empires, after all, survive and prosper by promoting their own economic and material interests in various ways, and their very purpose is to expand those interests...just as the very purpose of any business entity is to expand its interests, thereby enlarging its profits. War is one quick way of expanding one's interests...if it's a successful war. If not, it can lead to ruin, as many empires have discovered.

Ordinary people pay the price for that, in a great variety of ways. If they're in the way of some imperial objective, they get attacked. If they're of age, they get sent to war. They also sometimes reap the material benefits of it, if they happen to be positioned fortunately and on the winning side.

American troops in Vietnam were not positioned fortunately, and were not on the winning side (in the long run). Anyone who served there has my sympathy for having been sent on a fool's errand and for having been used. Likewise, anyone who is serving in Afghanistan. The best thing one could do for such people is bring them home to their families ASAP.

It's only aggressive empires who need to station their troops all over the world on other people's land. Such empires always believe themselves to be "the light of the world" at the time, but they are not. They're the oppressors of the world. Their troops should go home.

Note: I am not criticizing the soldiers who serve. I'm criticizing the bosses who send them out there.