US (and allied) failure in Afghanistan got me thinking about how, after taking time to reflect, the US re-evaluated the lessons from defeat in Vietnam. Hundreds of books and articles have been written on the topic. Here's a sample:
John Correll, "The Weinberger Doctrine", Air Force Magazine, 1st March, 2014.
E.J. Dionne, "Kicking the Vietnam Syndrome", The Washington Post, 4th March, 1991.
Frank Hoffman, "A second look at the Powell Doctrine", War on the Rocks, 20th February 2014.