The United Nations Convention on Conventional Weapons (CCW) of 1980 regulates the use in armed conflict of certain conventional arms deemed to cause excessive suffering to combatants or indiscriminate harm to civilian populations. In December 2001, CCW high contracting parties concluded a Second Review Conference of the Convention in Geneva. Unlike the First Review Conference of 1995-1996, which focused on land mines and blinding laser weapons, the Second Review Conference attracted modest public and media attention. This difference was due in part to the fact that the conference principally focused on an improvement of the Convention thatwasjuridicalin nature, lacking an “optical” quality typically associated with proposals to restrict particular weapon systems. Even so, the conference generated substantial governmental interest and a remarkable development in international humanitarian law: expansion of the scope of application of the Convention, previously limited to conflicts between sovereign states, to noninternational armed conflicts. This expanded scope, if widely observed, should influence the use of particular weapons in internal armed conflicts. More important, the expansion reinforces the trend toward reducing the distinction between international and noninternational armed conflicts for purposes of the rules governing the conduct of hostilities. This trend carries implications both for which weapons are used in warfare and how, and for the international criminalization of violations of the rules of noninternational armed conflict.