We picked up a slew of bad habits in Viet Nam and Ranger School embedded most of them as did IOBC -- interestingly, because of far less Armor branch exposure in Viet Nam, AOBC did not fall into that trap. We are picking up more rand even worse habits as a result of Afghanistan and Iraq.

There is, as noted a considerable difference between SOF operations conventional operations. Small unit patrols are one thing and the tactical efforts are similar -- but both do a great many things aside from conducting patrols (though in the current wars no one is really doing much else...). That is dangerous, a mid or high intensity conflict will shred units with little besides current experience. Thus far in 2011, all ISAF has incurred 509 fatalities (combat / non combat not diffrentiated). In a mid intensity conflict like Viet Nam or Korea, one Division could endure that many killed -- or more, many more -- in a quarter. In WW II like conditions, it could reach that figure in a week or two.

The current fights obviously provide little to no use of tripods -- except for the M2 and Mk19. One has to wonder if the M240 were more often tripod mounted if as many .50s and 40mm would be about.

Chris jM has it right. As he points out, defense is far from the only use for tripods. The use of really accurate fire as a support measure in the offense has great merit -- you cannot provide accurate long range fire from a bipod so no thinking Commander is going to allow his MGs to fire over the heads of advancing troops unless the guns are tripod mounted. That occurred often in WW II and Korea, only rarely in Viet Nam and is even more rare today -- yet it is needed capability. Sometimes the organic stuff is all that's available...

As jcustis notes:
As for application, that tends to be difficult to do when pre-deployment training takes the fore.
That's reality -- and that is the danger. Training for the here and now should not be in lieu of needed training, it should be in addition to. We often forget that; we forgot it post Viet Nam. We're forgetting it today. Hopefully we will not repeat that 1970-90 mistake.