We're not quite repeating Vietnam. Although both wars have a lot in common, the major difference is that with Iraq, there is no draft. Only the poor souls who voluntarily enlist have to go over there.

But if you read that article I linked, it says a cautious hydroponics store owner contacted his congressman who told him there isn't a desire for a repeat of that. I would imagine that's true, since the overall trend since then has been toward leniency and decriminalization.