excellent advice from william polk, expert on counterinsurgency: “Even in the tactical short run, I believe, trying to defeat the Taliban is not in America’s interest. The harder we try, the more likely terrorism will be to increase and spread. As the history of every insurgency demonstrates, the more foreign boots there are on the ground and the harder the foreigners fight, the more hatred they engender. What actually brought all the insurgencies, including the one in Vietnam, to a halt was the withdrawal of the foreigners.” Entire letter.