This book covers four major failed post-WW2 counterinsurgencies (France in Algeria, Britain in Cyprus, USA in Vietnam and again in Iraq) and attempts to identify the causes. Some of them are common across all four (prioritizing military operations over civil projects, ignoring legitimate expertise in favor of wildly optimistic theorizing, accepting the biased opinions of local minorities as representative of the whole population) while others are unique to each conflict or at least to one of the intervening countries (introducing Turkey into the negotiating table for Cyprus, failure to establish a functional security force in Vietnam and Iraq).
The author betrays some of his political views in the text, for example he regards "mainstream media" as being hostile to American intervention in Iraq (was he watching the same news shows or reading the same papers as everyone else?), and while quite critical of the Bush II administration he also takes some potshots at Clinton that are completely pointless in this context. Finally, the author seems to back the opinion that there was ever a chance for Iraqis to wholeheartedly accept a government imposed by a foreign power and backed by foreign troops, and never makes the connection between the partisan "militias" that emerged after the invasion and the "insurgents" that fought the occupying forces. Probably, none of that should come as a surprise in a mid-brow book clearly aimed at the military and amateur military historians, but it made me question the seriousness of the work.
A little stranger is the criticism of British foreign policy in the Cyprus emergency. Corum accuses Prime Minister Anthony Eden of a pro-Turkish, anti-Greek bias in consulting the Turkish government along with the Greek to find a consensus solution instead of just handing over the island and its large ethnic Turk minority to Greek-backed guerrillas without consulting Britain's regional allies, at a time when Turkey was a major regional power (and the only one not hostile to Britain) while Greece was just finished fighting a civil war that left the country in ruins.
Perhaps another book may explore the differences between fighting an insurgency as a national government as opposed to a foreign occupation or a long-term colonial power, but this one makes no such distinction. In my opinion, this is the biggest weak point.