Nuclear Weapons and The United Kingdom - Legality

Legality

See also International Court of Justice advisory opinion on the Legality of the Threat or Use of Nuclear Weapons

See also Nuclear Non-Proliferation Treaty

After the British government announced its plans to refurbish its Trident SLBM missiles and build new submarines to carry them, it published a white paper The Future of the United Kingdom’s Nuclear Deterrent in which it stated that the renewal is fully compatible with the United Kingdom's treaty commitments and international law. These arguments are summarised in a question and answer briefing published by UK Permanent Representative to the Conference on Disarmament

• Is Trident replacement legal under the Non Proliferation Treaty (NPT)? Renewal of the Trident system is fully consistent with our international obligations, including those on disarmament. ...
• Is retaining the deterrent incompatible with NPT Article VI? The NPT does not establish any timetable for nuclear disarmament. Nor does it prohibit maintenance or renewal of existing capabilities. Renewing the current Trident system is fully consistent with the NPT and with all our international legal obligations. ...

At the start of the House of Commons debate to authorise the replacement of Trident, Margaret Beckett stated:

Article VI of the NPT imposes an obligation on all states: “to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a Treaty on general and complete disarmament". The NPT Review Conference held in 2000 agreed, by consensus, 13 practical steps towards nuclear disarmament. The UK remains committed to these steps and is making progress on them. We have been disarming. Since the Cold War ended, we have withdrawn and dismantled our tactical maritime and airborne nuclear capabilities. We have terminated our nuclear capable Lance missiles and artillery. We have the smallest nuclear capability of any recognised nuclear weapon state accounting for less than one per cent of the global inventory. And we are the only nuclear weapon state that relies on a single nuclear system.

The subsequent vote was won overwhelmingly, including unanimous support from the opposition Conservative Party.

The Government position remains that it is abiding by the NPT legally in renewing Trident and Britain has the right to possess nuclear weapons, a position reiterated by Tony Blair in PMQs on 21 February 2007.

In contrast, reports by Philippe Sands QC, and by Rabinder Singh QC and Professor Christine Chinkin, used in the case against, were commissioned by the activist groups Greenpeace and Peace Rights respectively. Both groups are opposed to the renewal, use, or proliferation of nuclear weapons.

Furthermore, the British Government and NATO do not recognise advisory opinion of the ICJ, as interpreter of IHL and referred to by Sands et al., (see Advisory Opinion) with regard to use of nuclear weaponry as legally binding.

This position is held in common with all five nuclear states as defined in the NPT. However, only the United Kingdom has expressed its opposition to the establishment of a new legally binding treaty to prevent the threat or use of nuclear weapons against non-nuclear states by its vote in the United Nations General Assembly in 1998.

One view is that the white paper The Future of the United Kingdom’s Nuclear Deterrent stands in contrast to two counsel's opinions. The first, commissioned by Peacerights, was given on 19 December 2005 by Rabinder Singh QC and Professor Christine Chinkin of Matrix Chambers. It addressed '...whether Trident or a likely replacement to Trident breaches customary international law'

Drawing on the International Court of Justice (ICJ) opinion, Singh and Chinkin advised that:

The use of the Trident system would breach customary international law, in particular because it would infringe the "intransgressible" requirement that a distinction must be drawn between combatants and non-combatants.

The second opinion was commissioned by Greenpeace and given by Philippe Sands QC and Helen Law, also of Matrix Chambers, on 13 November 2006. The opinion addressed

The compatibility with international law, in particular the jus ad bellum, international humanitarian law (‘IHL’) and Article VI of the Treaty on the Non-Proliferation of Nuclear Weapons (‘NPT’), of the current UK strategy on the use of Trident...The compatibility with IHL of deploying the current Trident system... the compatibility with IHL and Article VI NPT of the following options for replacing or upgrading Trident: (a) Enhanced targeting capability; (b) Increased yield flexibility; (c) Renewal of the current capability over a longer period.

With regards to the jus ad bellum, Sands and Law advised that

Given the devastating consequences inherent in the use of the UK’s current nuclear weapons, we are of the view that the proportionality test is unlikely to be met except where there is a threat to the very survival of the state. In our view, the ‘vital interests’ of the UK as defined in the Strategic Defence Review are considerably broader than those whose destruction threaten the survival of the state. The use of nuclear weapons to protect such interests is likely to be disproportionate and therefore unlawful under Article 2(4) of the UN Charter.

The phrase "very survival of the state" is a direct quote from paragraph 97 of the ICJ ruling. With regards to international humanitarian law, they advised that

it hard to envisage any scenario in which the use of Trident, as currently constituted, could be consistent with the IHL prohibitions on indiscriminate attacks and unnecessary suffering. Further, such use would be highly likely to result in a violation of the principle of neutrality.

Finally, with reference to the NPT, Sands and Law advised that

A broadening of the deterrence policy to incorporate prevention of nonnuclear attacks so as to justify replacing or upgrading Trident would appear to be inconsistent with Article VI; b) Attempts to justify Trident upgrade or replacement as an insurance against unascertainable future threats would appear to be inconsistent with Article VI; c) Enhancing the targeting capability or yield flexibility of the Trident system is likely to be inconsistent with Article VI; d) Renewal or replacement of Trident at the same capability is likely to be inconsistent with Article VI; and e) In each case such inconsistency could give rise to a material breach of the NPT.