Prohibiting low-yield nuclear weapons is a step in the right direction

Malcolm Davis raises some important issues regarding our proposal for a treaty restricting low-yield nuclear weapons. We’re word limited on our response, so we strongly recommend the longer discussion paper for subject-matter experts as it examines comprehensively all of the issues that Dr Davis quite rightly raised.

There are of course a number of views put forward by Davis that we’d associate ourselves with; such as the role of traditional nuclear deterrence, and the need to pursue tools in addition to arms control for reducing nuclear risk (he referred to tactical ballistic missile defence systems for instance).

And yet, the scepticisms expressed with respect to the proposed treaty appear to reflect a misunderstanding of the relationship that exists between this proposed arms control measure and overall military strategy.

His scepticisms can be broadly placed into three categories: 1) the philosophy underpinning the proposed treaty; 2) the technical and verification measures necessary to make it viable; and 3) the challenge of successfully bringing the treaty into force.

We’ll briefly respond to each. First, the view put forward that we ‘reflect a uniquely Western perspective on the role of nuclear weapons…’ and that we ‘…have the luxury of debating legal, ethical and moral arguments for a nuclear taboo and abolition’ can be dealt with very quickly.

While others do put forward moral or humanitarian arguments in support of nuclear disarmament, our analysis is based firmly, and exclusively, on principles of military logic and strategy, with the aim of enhancing international security. Indeed we acknowledge the role that extended nuclear deterrence is thought to play in supporting non-proliferation, and understand that some countries with nuclear weapons seek to maintain arsenals with a non-strategic component for a variety of reasons. Nevertheless, low-yield weapons are a unique class of non-strategic nuclear weapons (NSNWs) that carry special risks which greatly outweigh any marginal benefit. Prohibiting the development and retention of nuclear weapons with yields below 5 kilotons therefore strengthens security overall.

Dr Davis also raises concerns that the existence of ‘selectable-yield’ (variable-yield) weapons makes a 5 kiloton yield-limit easy to cheat, and also argues that China’s nuclear arsenal wouldn’t be verifiable. But here we’re getting ahead of ourselves. Before we ask the question how will a country cheat on a treaty prohibiting low-yield weapons, we first need to ask why will they cheat? How much does a country that is party to the proposed treaty really gain through clandestine acquisition, testing or use of low-yield weapons?

The answer is ‘almost nothing’. Since low-yield weapons are technically complex, any state with the capacity to develop low-yield weapons will also possess much more powerful strategic weapons. Thus no state derives benefit by surprising a nuclear-armed adversary with a low-yield strike as it can only invite a devastating nuclear response that is of an exclusively strategic character (making first use of low-yield weapons totally unacceptable).

On this point Davis seems to have misinterpreted our paper, suggesting that we think that ‘a legal mechanism would deter cheating’. The treaty’s greatest deterrent to cheating is the fact that it’s effectively self-enforcing; strengthening the nuclear deterrent of countries that are party to it. What the proposed legal mechanism does do is give a decision-maker in a high-pressure crisis situation an alternative option to massive nuclear escalation should the use of low-yield weapons actually occur. Taking India and Pakistan as an example; once India had ratified the proposed treaty, Pakistan would know that if it attacked India with a low-yield weapon India would have no choice but to respond at higher yields. Also, India could demand an immediate response by the wider international community (on the grounds that low-yield weapons were illegal), which may prevent nuclear escalation, and certainly prevent a Pakistani military victory.

Davis also raises many issues with respect to negotiating a treaty, or in his words making ‘such a treaty actually happen’. He specifically points to North Korea, Israel, India, Pakistan, and potentially Iran as countries unlikely to ratify the treaty.

While we’d like to respond fully here (as well as to his points on Russia and on the comprehensive test ban treaty), these individual cases will need to be saved for another post, and are in any case covered in the full discussion paper. But again, there’s a question which needs to be asked first before any of this analysis can take place. Assuming that these countries don’t ratify a treaty banning low-yield weapons, what would be the impact? The shortest answer would be that all of the countries mentioned are either not party to, or aren’t in compliance with, the Nuclear Non-Proliferation Treaty (NPT). It would be very difficult to mount a credible argument that because of these five exceptions it would be preferable if we never had an NPT regime at all.

Crispin Rovere and Kalman A. Robertson are at the ANU’s School of International, Political & Strategic Studies and are the authors of the ASPI Policy Paper ‘Non-strategic nuclear weapons: the next step in multilateral arms control’. Image courtesy of Flickr user Beautification Syndrome.