Sweden joins NATO

William Freer, Research Fellow in National Security at the Council on Geostrategy, provides a debrief assessing Sweden’s accession to NATO.

What has happened?

On 7th March 2024, Sweden officially became a full member of NATO. Both Finland and Sweden had jointly applied to NATO in May 2022, shortly after Russia’s renewed aggression against Ukraine. Finland became a full member in April 2023, but Sweden’s application was delayed by Turkey and Hungary.

The decision by Finland and Sweden to apply for NATO membership represents a seismic shift in their foreign and defence policy; both nations had long pursued neutrality. It is a serious geostrategic setback, even an own-goal, for Russia.

Why does this matter for the United Kingdom? 

Sweden joining NATO is a great benefit to the defensive power of the alliance, and its ability to deter Russian aggression. Sweden adds significant military capabilities, which it is strengthening through increasing defence expenditure to hit NATO targets (before 2022 Sweden spent 1.2% of GDP on defence). Sweden’s armed forces will soon expand to total four combat brigades, around 100 combat aircraft (the Saab Gripen) and a small but capable navy centred around stealthy corvettes (the Visby-class) built to fight an asymmetric conflict in the Baltic archipelago.

Geography is the other great benefit of Sweden joining NATO. With both Finland and Sweden as members, NATO dominance over the Baltic Sea is greatly strengthened. In the event of conflict, Russian forces in the exclave of Kaliningrad would be even more isolated and Russian warships operating in the Baltic would be incredibly vulnerable.

Sweden and the United Kingdom (UK) already had a close military relationship, and Britain gave security assurances to Sweden (and also Finland) while it waited to join NATO. Sweden joined the British conceived Joint Expeditionary Force (JEF) in 2017 (a military partnership designed to support Nordic and Baltic participation in out of area operations, but now moving more towards reinforcing Baltic security) and British defence company BAE Systems has a significant subsidiary in Sweden. Sweden joining NATO now opens up the prospects for even deeper cooperation.

Looking ahead

This shift in Sweden’s defence policy, particularly the longer term impact it will have on the political appetite in Stockholm, opens up new possibilities which the UK should take full advantage of.

This could include similar arrangements to those in place with Norway for military training/deployments. The UK could even explore the possibility of creating permanent JEF formatons in the air, at sea, and on land, forward deployed in Sweden to dominate the Baltic. For example a JEF armoured division made up of Swedish, British, Finnish (and potentially other JEF member) brigades positioned in Finland would present Russia with new geostrategic problems. Amphibious forces positioned in Sweden would also reduce pressure on the Suwalki gap (the link between Poland and the Baltics) allowing for the reinforcement of the Baltics by sea.

Sweden has been a strong supporter of Ukraine, sending a relatively large proportion of modern tanks, armoured vehicles, artillery shells – and potentially soon aircraft too. Having another country in NATO which reinforces the focus on Britain’s areas of strategic priority – the northern and eastern flanks of the alliance – strengthens the UK’s hand and reduces Russia’s capacity to sow instability.

William Freer is a Research Fellow in National Security at the Council on Geostrategy.