Sweden’s Choice: NATO or the Nuclear Ban?

Citing the deteriorating security situation on its borders and a growing threat from Russia, Sweden is currently staging its largest military exercises in 23 years, the three-week-long Aurora-17, which is scheduled to end on 29 September.

Aurora-17 also includes the participation of the US military as well as from other neighbouring armed forces. They are largely a continuation of a decades-long effort to narrow the differences between NATO and Sweden, without touching on the more thorny issue of Sweden’s membership in the Alliance.

Yet at the same time that Sweden is seeking to align its military with NATO’s, it is also involved in another debate which could gravely complicate Stockholm’s relationship with the Atlantic Alliance. That is, a debate over the ratification of the Treaty on the Prohibition of Nuclear Weapons, which opened for signature this week, and is supported by the government.

The treaty, adopted by 122 non-nuclear countries in July, includes prohibitions on the development, production, testing or use of nuclear weapons. Only 50 states need to sign and ratify the treaty in order for it to enter into force, a threshold that will easily be met.

It will, however, have no immediate impact on nuclear weapons possession – it is not binding on non-signatory states – and will not overturn disarmament politics overnight. No nuclear weapon state, as recognised under the Nuclear Non-Proliferation Treaty (NPT), has participated in treaty negotiations and none intends to sign it.

They have consistently referred to the ban treaty as a distraction from existing multilateral disarmament commitments under which they are already committed to a nuclear-free world, albeit with an unspecified timeline.

Of course, there are also four other nuclear-weapons states outside the NPT framework: Pakistan; India; Israel; and North Korea. NATO states, as well as Japan and South Korea, which benefit from the protection offered by the nuclear arsenals of their nuclear allies, have taken the same line. The Netherlands did participate in negotiations, but ultimately voted against the final treaty text.

Sweden, on the other hand, has actively taken part in the treaty’s negotiations, voted to adopt the final treaty text in July and announced that it will carry out an assessment of the resulting document, with a view to signing it.

Article 1(e) of the ban treaty forbids states to ‘[a]ssist, encourage or induce, in any way’ other states to carry out activities related to nuclear weapons. This could present countries such as Sweden with a challenge to their continued cooperation with NATO.

Sweden is part of NATO’s Partnership for Peace programme, allowing it to be ‘one of NATO’s most active partners and a valued contributor to NATO-led operations’. The programme allows Stockholm to regularly take part in large-scale exercises with its NATO neighbours, including Aurora-17, supply training to NATO forces and have military assets designed and manufactured in cooperation with or by NATO members, with a view to achieving interoperable platforms.

Sweden is not, however, covered by NATO’s Article 5 commitment, under which nuclear-armed allies could plan to use nuclear weapons in defence of non-nuclear member states under attack.

This crucial difference may be enough for Sweden to still sign the nuclear ban treaty, if mutual defence is seen to be the only element of NATO cooperation equivalent to ‘assist, encourage or induce’ nuclear deterrence.

But other peripheral areas of cooperation should also be considered, such as Sweden’s ongoing cooperation with both the UK and the US on disarmament verification programmes, or its close cooperation with NATO states on issues of non-proliferation and disarmament in the NPT process or through the EU.

Sweden works even more closely with Norway and Denmark under a common Nordic banner, and has issued joint statements on disarmament in the past. It will be harder to reach common consensus in these relationships if Sweden signs the nuclear ban treaty.

Sweden’s Foreign Minister Margot Wallström has made it clear that she believes Stockholm can still fulfil its defence and security cooperation commitments while becoming a signatory to the nuclear ban treaty.

But it is not clear that her view is shared by her Cabinet colleagues in Stockholm. Defence Minister Peter Hultqvist is reportedly opposed to signing the treaty, while Prime Minister Stefan Löfven has been quiet on the issue.

The nuclear ban treaty and Sweden’s involvement has been branded by local media as the ‘ambition of the Foreign Minister’. Importantly, however, the Swedish Parliament will need to ratify the treaty before Sweden can officially accede to it.

Sweden’s support for the nuclear ban treaty cannot therefore be taken for granted. In an effort to influence and apply pressure, US Secretary of Defense James Mattis issued a stark warning to Stockholm that ‘signing the treaty could directly impact Sweden's relationship with NATO’, including joint defence industrial programmes and close any option for future NATO membership.

It is yet to be seen how much impact such warnings will carry in the Swedish parliament, or whether they will be perceived as interference by Washington. Wallström reminded domestic audiences in an August op-ed that Sweden should make its own security and foreign policy assessments as ‘an alliance free country’, an assessment that does not call for US influence.

Sweden, being perhaps more closely connected to nuclear weapon states and their allies on nuclear issues than most other potential ban supporters, will set a precedent for how Article 1(e) will be interpreted by signatories, and potentially tip the scales for other countries that are on the fence about joining the treaty.

Should Sweden sign and ratify the nuclear ban treaty, the country will send a clear signal to the world that current disarmament efforts are not enough, and that more needs to be done. However, doing so would also add a significant obstacle to pursuing ever-closer relations with NATO.

In fact, it would almost definitely rule out any possibility of Swedish NATO membership. This is a significant decision to make at a time when there is broad consensus in Sweden that the security environment around it is deteriorating, and that cooperation with the alliance is crucial to its defence.

The views expressed in this Commentary are the author’s, and do not reflect those of RUSI or any other institution.