P.S. Must I remind that all the Empires since Alexander the Great -- who had to take extreme measures: exterminate the population and marry a Afghan princess (UGH!) -- have broken their teeth while trying to conquer a very old kingdom with very high mountains, lots of "nerve" and places to hide, etc., from the Brits, to the Soviets and now the North- American loonys ( "What's up, doc?!").
A very good comment: https://www.theguardian.com/commentisfree/2017/apr/14/the-mother-of-all-bombs-big-deadly-ineffective