Just War Theory (JWT), or as these authors term it the Just War Tradition has a long pedigree both as a fulcrum around which the Christian approach to war is debated and as a framework for initiating and conducting military actions; it is in the latter context that this book seeks to situate itself.
The authors are not both academics but are certainly distinguished in their field as their CVs demonstrate. Charles Guthrie has served in both the Welsh Guards and SAS has held a number of senior defence position culminating as Chief of the Defence Staff from 1997 to 2001 for the UK military, since then he has been member of the House of Lords. Michael Quinlan's reputation is no less distinguished. For over 35 years he was a civil servant acting at times as both Policy Director for the Ministry of Defence and as Permanent Under-Secretary of State. Since 2004 he has been a Senior Fellow of the International Institute of Strategic Studies.
At only just 50 pages it is I think fair to state that this is not a tour de force in JWT. Truth be told there is not much in the text that I consider to be noteworthy. This is not a work of ethical or theological theory; for example, pacifism is not really even considered viable - but is rather simply a case of standing back and watching evil unfold (p 24). I'm not entirely sure Martin Luther King or Gandhi would agree.
In terms of the author's survey of JWT itself they survey the decision to go to war (jus ad bellum) in somewhat greater detail than the the subject of military ethics that is the concern of the jus in bello. The jus in bello discussion is limited to the discrimination criterion, that is the requirement to limit military operations to combatants and other "actively involved" and secondly the continued need for proportionality. At first given the military background of the authors, together with those of the endorsers (that number among them other Chiefs of Staff, this may seem surprising. However, with the Jus ad bellum criteria the authors have focused on those deemed to be in legitimate authority or, in military jargon, those in command responsibility. My concern with such a emphasis is it creates an illusion of ethical neutrality on the part of the soldiers who actually do the killing of war - judging by the complete omission of their role it would seem that they are passive subjects to the JWT - the Nuremberg hearings, it would seem, never happened. With the contemporary conduct of some fragments of the military forces in recent conflict - I am thinking for example of Abu Graib, such an omission from a text on the military understandings of JWT is an extremely significant and regrettable omission. If given their experience as military commanders and or policy officials it is surely here that their expertise would be relevant.
Given its omissions and general unremarkable nature I do question why this book was written. I do wonder given its context in a time of continuing national debate over Iraq (at the time of publication) even given its paucity of references to current conflicts whether it is a subtle reminder by two seasoned "insiders" the tendency to label every war as Just does not make it so and that more than media soundbites are required to make the case. But that, of course, is speculation.