Divide and conquer was a standard in all colonial wars. But you end with a divided country with ethnic tensions: an ideal environment for guerrilla fighters.

In the "good old times" that the article descibes guerrilla was a local affair. Nowadays nearly every guerrillero knows about the theories from guerrilla handbooks from Mao, Che and others. So their response is more sophisticated.

In Iraq or Afghanistan the problem is quite similar to that in Vietnam: government troops are rather unreliable and unmotivated. Yet I think that part of this problem is self-created. The US has pushed for a centralized government and many of the soldiers feel only connected with their region/tribe. The new tribal approach in Iraq may be a better solution.