Many assume that in international politics, and especially in war, "anything goes." Sherman famously declared war "is all hell." The implication behind the maxim is that in war there is no order, only chaos; no mercy, only cruelty; no restraint, only suffering.

Ward Thomas finds that this "anything goes" view is demonstrably wrong. It neither reflects how most people talk about the use of force in international relations nor describes the way national leaders actually use military force. Events such as those in Europe during World War II, in the Persian Gulf War, and in Kosovo cannot...