Why hasn't the U.S. military gotten smarter about guerrilla warfare?

In the Vietnam years, Westmoreland and other top U.S. officials were forever seeking an elusive “crossover point” — the moment when their Vietnamese foes would be losing more fighters than they could replace and so would have to capitulate. America would win by fighting a war of attrition.

But that didn’t work in Vietnam, and it’s not working in Afghanistan. More than a decade after U.S. forces swept into Kabul, what began as a ragtag remnant insurgency has grown stronger and continues to vex the most destructively powerful, best-funded military on the planet. All of America’s tactical gains and captured territory, especially in the Taliban heartland of Helmand province in southern Afghanistan, haven’t brought the country anywhere near victory…

The conflict in Afghanistan began with its American commander declaring, “We don’t do body counts,” but a quick glance at recent U.S. military press releases touting supposed high-value kills or large insurgent body counts indicates otherwise.

As in Vietnam, the United States is once again betting on a war of attrition. But the enemy hasn’t bought in. Instead of slugging it out toe to toe, in large suicidal offensives, the Haqqanis and their allies have planned a savvy, conservative campaign meant to save fighters and resources while sending an unmistakable message to the Afghan population and the American public.