Nuclear Strategic Stability

Nuclear Strategic Stability and a 10-point Code for Responsible Nuclear Armed States

(This is a shortened version of the first element of a paper first published by the Council on Strategic Risks 7 Jan 2019, and updated for presentation to the UN First Committee in October 2019)

As the definition of global strategic stability has proved very difficult, the last valiant attempt to quantify it being a series of papers edited by Elbridge Colby & Michael Gerson in 2013[1],  a more constrained definition of Nuclear Strategic Stability would be useful.

An initial working definition is:

Nuclear Strategic Stability (NSS) is a metric of international relations and is high where the risk of any conflict being initiated using nuclear weapons or escalated to the nuclear level is as low as is achievable.  Every posture, capability or declaratory change should be assessed against this metric; Nuclear Armed States (NAS) should always strive to improve NSS.

Fundamental to the adoption of NSS as the overriding metric is the understanding that it does not affect deterrent relationships nor individual state security.  Indeed, the higher the NSS, the more capable becomes strategic nuclear deterrence.

Evidently the highest NSS would be achieved once nuclear weapons were no longer fielded by any state (though this, without other compensating security actions might make the world less stable in broader conventional conflict terms).  Direct progress from today’s’ state to “Global Zero”, however, would not be a continuous improvement in NSS.  Even with a carefully constructed pathway aimed at maintaining optimum NSS through an omnilaterally agreed plan will have spikes in instability, especially at low numbers.

An analysis of every current capability, posture and policy should be compiled and marked against optimum NSS short of zero.   Six elements of NSS are proposed that NAS should use to guide their current and future actions.  These are all designed to maintain or reduce the tensions from capabilities, policies or posture which weaken NSS and are:


Within these six elements a 10-point Code of Responsible Nuclear Armed States is postulated.  Adoption of such a Code would identify where NAS’ doctrine, declaratory policy, posture and capability was most and least supportive of NSS and where, by adoption of the Code, and following its articles through, NSS can be improved without net decrease in NAS state security.


10-point Code of Responsible Nuclear Armed States


  1. NAS will always, and in all circumstances, exercise maximum restraint in rhetoric, posture, activity and readiness, in steady state and especially in crisis.
  1. NAS will ensure that sufficient unambiguous communication pathways exist at the level of the National Control Authority for crisis communications between NAS.


  1. NAS will not employ nuclear weapons as levers of statecraft, except as strategic deterrents to other NAS.


  1. NAS posture will reassure non-NAS of the veracity of their declaratory policy, particularly regarding political control of systems and release procedures
  2. NAS will adjust NSAs, posture, and ORBAT to maximise reassurance to non-NNAS


  1. NAS undertake to move and retain strategic weapons systems to the lowest readiness matching their declaratory policy which in turn is reviewed to maximise reassurance and restraint.


  1. NAS will look for areas of mutual reciprocity in posture, policy and doctrine which bolster strategic stability and reduce the salience of nuclear weapons in their security and defence metrics
  1. NAS will seek an agreement isolating strategic sensor and C3 systems from attacks and entanglement with emerging technology which could lead to misinterpretation and escalation into the nuclear domain.


  1. NAS will sketch out likely reduction paths and progress them when multilateral and omnilateral opportunities allow
  1. NAS will seek further opportunities; unilateral, multilateral and omnilateral, to reduce complexity and variety of nuclear arsenals towards the most stable – single capability system, politically controlled, strategic and most invulnerable. From this platform alone is the NPT Art VI objective possible.

[1] Elbridge A. Colby, Michael S. Gerson, Strategic Stability: Contending Definitions, SSI and USAWC Press, Feb 2013