Seven decades of proliferation have led to nine nuclear armed states. The five NPT Nuclear Weapon States (NWS) each offer their own negative security assurances to the world outlining the limits to the use of nuclear weapons. Declaratory policies are expressed with variable degrees of clarity and formality – sometimes existing only in the public announcements of a head of state – but they remain an important practice for every possessor of nuclear weapons.
There are two benefits to offering declaratory policy. First, it is part of the signalling essential to an effective deterrence posture. Without it, the posture of a nuclear armed state would remain a matter of guesswork. Unnecessary ambiguity can lead to escalatory threats, ultimately raising the likelihood of a nuclear exchange. Second, it discourages the further proliferation of nuclear weapons by assuring Non-Nuclear Weapon States (NNWS) and reducing their incentive to acquire nuclear weapons themselves. Declaratory policies are therefore simultaneously at the core of both deterrence theory and of the Non-Proliferation Treaty (NPT).
Yet NATO has never had a declaratory policy. Instead it has explicitly preferred thus far to rely on the three distinct declaratory policies of its nuclear member-states, despite their contrasting conditions-for-use; in fact, the contradictions between the postures of the three nuclear allies are regarded positively within NATO, as they allegedly contribute to ‘ensuring uncertainty in the mind of any aggressor’.
This report by Laurence Gerhardt, explores the need for a more explicit declaratory policy for NATO's nuclear member-states, in the interests of unity within the alliance and it's dual track commitment to both non-proliferation and deterrence.