A few websites referenced in this episode:
AEI's Critical Threats Project: https://www.aei.org/profile/frederick-w-kagan/
Institute for the Study of War: https://www.understandingwar.org/
Long War Journal: www.longwarjournal.org
A recent oped that Fred Kagan published in The New York Times: https://www.nytimes.com/2021/08/12/opinion/biden-afghanistan-taliban.html
And a recent column by Charles Lane in The Washington Post: https://www.washingtonpost.com/opinions/2021/08/17/bidens-presidency-us-foreign-policy-now-hinge-pulling-off-one-greatest-airlifts-history/