This work explains why the concern to minimize civilian casualties is solidly based in Western civilization's most fundamental principles of justice. The author interprets Augustine's just war theory, Vitoria and Suarez's "transitional" model of war, and offers explanation for the modern characterization of the combatant as a depersonalized instrument.

Why is it that soldiers may be killed in war but civilians may not be killed? By tracing the evolution of the principle of non-combatant immunity in Western thought from its medieval religious origins to its modern legal status, Colm McKeogh attempts to answer this question. In doing so he highlights the unsuccessful attempts to reconcile warfare with our civilization's most fundamental principles of justice.