Erudite, scholarly, thoughtful and definitively relevant examination of codes of conduct wrt to going to war - jus ad bellum, and conduct in a war - jus in bello. Walzer's personal journey emerged first from his opposition to US actions in Vietnam but led to an examination of the pursuit of war from Thucydides to modernity.
War invites barbarism, breaking both law and permissibility. Against this Walzer notes that circumstances do allow for rules of engagement, for example chivalry, , respect for civilians, captured and injured opponents, appeals to necessity, treatment of hostages, relationship towards neutral parties. Action does not occur in a vacuum and context can make a difference. Walzer draws on emblematic historic examples such as the dilemmas embedded conflict, avoidance of total war, treatment of captives and civilian populations, who is or is not immune from attack (yes to weapons manufacturers, no to those packaging rations; surprising no to sentries who should be captured or driven in) and under what circumstances, and signalling that there are consequences of breaching the limits of moral behaviour. Walzer broaches the concept of pursuing the lesser evil with trepidation, confronting acts such as the creation of fire storms in German cities by Britain's Bomber Command as reprisals for German bombing of British cities, Hiroshima and the shooting of hostages as a signal to the enemy to stop a similar practice Particularly intriguing from a moral stance were the questions of strategy, for example the use of siege which seeks to break the will of opponent forces by burdening them with suffering of the resident population - does one funnel refugees to the besieged city, does one blockade food; do you respect neutrality (ie: the Scandinavian countries in WW II) when doing so favours one's opponent (the Germans sourced much of their ore from Norway.), and given that your opponent did not do the same when it was to their advantage? (Hitler's advance through Belgium.)
Walzer's ideas are very much of our time, one also see changes since publication in the late 1970s, a slight parallax, which sets him off from the ideas of the past and from the evolving view of the present, ie: while one starts with consideration of intervention there are those who would make it a right (RPT), a position most nations have treated with caution. Walzer is neither the first nor the last word but he is thorough and his ideas present an excellent framework for an ethical exploration of the political and military decisions from a Western POV. And at the end that he considers pacifism and non-violence. Not all viewpoints are discussed, for example he does not discuss the Hindu precepts of ethical war (dharma-yudda) but neither are there explorations considering the warrior ethics of the Mongols or native Americans, nor medieval justifications for war in pursuit of tribute.
The sections are well organized and the language is clear and understandable, making this a modern classic that one can expect to return to on the issues of war. The only improvement would be an edition with commentary and responses by other authors; alternatively this is the sort of book that lends itself, in the right hands, to college and university courses Highly recommended!