WAR HAS always had rules, even if only to protect the dead. In The Iliad, for example, Homer tells us that Achilles' desecration of Hector's corpse angered the gods. Medieval churchmen sought to limit warfare to certain days of the week and evolved an entire just war theology to constrain the use of armed force. By the Age of Reason, international law "publicists" were busily expounding on the subject, and the 20th century opened with a substantial body of law governing both the right to initiate combat (jus ad bellum) and how armed force is applied (jus in bello). These "laws of war" were based both on custom and treaties and were accepted by all of the Great Powers--including the United States. In more recent years, however, fissures have opened between America and Europe over what the laws of war require with respect to when it is permissible to launch an armed attack, how warfare must be waged, and how the relevant legal norms should be enforced. Today, these disagreements are so fundamental that America and its partners in Europe can be said to operate under different legal codes.
