War on the Rocks has a good review of 'Michael Collins and the Anglo-Irish War: Britain’s Counterinsurgency Failure' by J.B.E. Hittle (Potomac Books, 2011):http://warontherocks.com/2014/01/les...glo-irish-war/

The emphasis is on intelligence, from the review:
The basic value of this book to most U.S. national security specialists are lessons they should seriously consider regarding intelligence and counterintelligence practices during counterinsurgency operations anywhere.
Link, don't forget you can order via SWC on Amazon:http://www.amazon.com/gp/product/159...tpwaronthec-20