Benefits of a “Presence of Fissile Material” Attribute for Warhead Confirmation in Treaty Verification

Recent work in attribute measurements for treaty verification has resulted in a growing list of potential warhead attributes and increasingly complex measurement methods for confirming them. However, the ability to successfully negotiate a monitoring regime is often inversely related to the number of attributes and the complexity of their measurement methods. We suggest that instead of increasing the number of detailed attributes, we cut directly to confirming the defining property of a viable warhead pit; the presence of fissile material. We review the benefits and plausibility of warhead confirmation based on two attributes only: the presence of fissile material and the presence of high explosives. We also provide a preliminary review of the technical options for confirming the presence of fissile material and the associated technology-based and potential policy-based challenges to implementation.