In the coming months and years, the United States and its North Atlantic Treaty Organization (NATO) allies will discuss, and U.S. and Russian Federation negotiators may enter, the next frontier in nuclear arms control: regulating small, “tactical” nuclear weapons. This framework Article is the first squarely on the subject in the legal literature. My core arguments are that (1) to date the bilateral Washington–Moscow arms control legal regime has primarily regulated strategic (long-range) nuclear delivery vehicles (bombers, missiles, and submarines) rather than warheads; (2) contrary to common assumption, the legal regime has regulated a small number of tactical delivery vehicles (jet fighters and other short-range systems) with arguable strategic relevance, providing a regulatory precedent; (3) the nuclear tactical versus strategic distinction in Cold War policy and the legal architecture is eroding and should be abolished; and (4) now that all nuclear weapons have “strategic” (that is, major) significance, and in view of the enduring “loose nuke” threat and other risks, the arms control legal regime should be expanded to regulate and reduce what we now consider tactical nuclear arms. Nonlegal steps—confidence-building measures and parallel unilateral reductions—may pave the way, but tactical nuclear weapons ultimately ought to be regulated via the new treaty I outline.
Extension of the legal regime to regulate all tactical delivery vehicles and warheads would be revolutionary. Warheads are much smaller than nuclear delivery vehicles, which can be readily observed from space. Warheads are therefore easier to conceal or steal, and they present unique verification challenges.
Resolution of the verification problem in a new treaty will be tough. But it also presents an opportunity: creation of what I term Nuclear Information Stability (NIS) between the United States and Russia, a condition characterized by continual communication and common understanding of the number, location, and operational status of nuclear hardware. The superpowers built 100,000 nuclear warheads during the Cold War and retain thousands of warheads today to mitigate uncertainty and reduce risk of a successful surprise attack— rationales for large stockpiles that would be challenged by NIS. Ultimately, I argue, NIS could allow the United States and Russia—and other nuclear states to which the concept could be exported—to see a realistic path from Mutually Assured Destruction (MAD) to a day-to-day state of Mutually Assured Security (MAS).