General Petraeus has been depicted as a great military thinker who came up with the strategy that won the war in Iraq. He famously replaced CT (counterterrorism) with COIN (counterinsurgency) which sought to win the hearts and minds of the local population — in other words to help us, and turn against those who are fighting us.
Well, it did nothing of the sort. The turning point in Iraq actually came only after the surge, which increased our boots on the ground, and the Sunni Awakening, in which we bribed the tribal chiefs of several Sunni communities to work with us. All the other stuff, the many scores of billions the U.S. spent on building schools and clinics (but not providing salaries for teachers and nurses), paving roads, digging wells and so on mainly enriched American contractors, but swayed few Iraqi minds. Indeed, Iraq is leaning ever more toward Iran and Iraqi fighters are helping sustain the Assad regime in Syria. We could not even persuade the Iraqi government to allow some of our troops to stay. Petraeus’ COIN hardly flipped their hearts and minds.
When Petraeus moved to Afghanistan he brought COIN with him, where it fared even worse. The strategy suffered, among other things, from the fact that its goals were never clear. Some days it was viewed mainly as a way to gain intelligence. Sometimes COIN was interpreted as a mandate to become closely involved with the local population, learn their culture, respect their traditions, and follow their lead. And sometimes the goal was to turn Afghanistan into a Little America, with Western-style democratic elections, respect for human (and especially women’s) rights and free markets. It took ten years, half-a-trillion dollars, and thousands of lives (American and Afghan) to learn that none of these goals can be achieved.
Last but not least, General Petraeus was one of the generals who helped box in President Obama, making it very difficult — in the end, politically impossible — for him to refuse to increase our troop levels in Afghanistan. Indeed, Petraeus is reported to have leaked information and made multiple calls to newspaper columnists in a systematic campaign to pressure the president to authorize the surge.