The UK and European Security: Five Key Lessons from the Ukraine War

Strength in unity: UK Prime Minister Rishi Sunak and the Ukrainian President Volodymyr Zelensky visit Lulworth Camp in Dorset. Image: Simon Walker / No 10 Downing Street / CC BY-NC-ND 2.0

With European security undergoing profound changes as a result of the current conflict, how should the UK look to navigate the changing order?

Just four weeks ago, the UK media was full of articles to mark the third anniversary of the UK leaving the EU. With a growing appreciation of the economic costs of Brexit and a sense that the UK has yet to find a clear post-EU international role, many politicians and commentators lamented the 2016 referendum result. Picking up on the national mood, the government and opposition are looking for ways to rebuild ties with Europe, including through incremental steps on security and defence. The Conservatives are keen to improve security ties with the EU and bilaterally with France, with a summit planned for March, while Labour is promising a new security agreement with the EU and a strategic partnership with Germany.

Russia’s invasion of Ukraine and its wider threat to Europe have underlined the importance of moves to strengthen the UK’s security ties with European allies. The debate about this relationship, however, continues to be defined unhelpfully by the backward-looking Leaver/Remainer divide over the EU and how the UK should prioritise Europe over other regions, notably the Indo-Pacific. The reality is that in security terms, the Europe that the UK ‘left’ in 2016 no longer exists. European security has been transformed by the Ukraine war, and there will no return to the conditions that existed before February 2022.

With European security undergoing its most significant changes since the collapse of the Communist bloc over 30 years ago, now is the moment to have a clear-headed discussion on what the Ukraine war tells us about the developing nature of European security, and how the UK should look to navigate the changing order.

Lessons on European Security

1. The US remains the ordering actor for European security, but China and the Indo-Pacific are its priorities

Three decades after Europe vowed to learn the lessons of the Yugoslav wars and to forge common foreign and defence policies, and despite numerous treaty reforms, new toolboxes, various strategies and compasses, and the creation of the paraphernalia of a European foreign ministry, when war returned to Europe in 2022, the continent was unable to mount a coherent and effective immediate response. The countries of Europe were divided in their strategic assessments of Russia and their definitions of national interest around the conflict, lacked the key capabilities to respond, and above all did not initially share a willingness to respond. Without the military, diplomatic and economic leadership and support of the US, Ukraine would have been overrun by Russian forces, despite the valiant efforts of its military and civilian population, and Europe would have been deeply divided as a result. While the political and economic superstructure of Europe has expanded over recent decades, the foundations that define European security remain reliant on the US. This is not just a question of capabilities, but of strategic intent and political willingness to respond to military threats. For now, the US is focused on countering Russia, but with Washington’s key future challenge in Asia, Europe remains far away from managing its own security in a unified way.

2. The EU is a useful security actor, but is unlikely to become the central element of European defence

While the EU was left to the side as the war began, following the leadership of the US and some of its European allies, the Union has begun to make an important contribution to supporting Ukraine and reinforcing Europe’s security. As the war has progressed, the EU has played an important role in coordinating sanctions, promoting energy security and providing financing for arms supplies to Ukraine, and has belatedly established a military training mission for Ukraine. If the EU can overcome some difficult internal obstacles, it may be able to purchase ammunition to assist Ukraine. The war has, however, highlighted that the core of Europe’s security and defence lies outside the Union in the transatlantic community, a fact that Brexit has only accentuated, with European collective strategic action reliant on US leadership. With Russia threatening Europe, EU members Finland and Sweden have sought security guarantees from the US and the UK and have applied to join NATO.

While NATO has re-emerged as the central coordinator for European defence, the war has shown that it is nation-states that remain the building blocks of European security

3. European multilateral security is crucially underpinned by a patchwork of diverse security relations between nation-states

The Ukraine war has seen a renaissance for NATO. The Madrid Summit of 2021 underlined the Alliance’s newfound unity, while the Vilnius Summit this summer will focus on the delivery of a new force model to meet the changed security environment. While NATO has re-emerged as the central coordinator for European defence, the war has shown that it is nation-states that remain the building blocks of European security. Europe is starting to reconstitute its military forces, but this is being done by individual countries acting to deepen and extend a diversity of overlapping bilateral, mini-lateral and regional agreements, as well as working through the main multilateral frameworks of NATO and the EU. This pattern is playing out, in particular, in arms procurement as European states look to cement security ties with their neighbours and the leading European security powers – notably the US – through new agreements and strategic weapons purchases, rather than managing procurement exclusively through joint processes in the EU or NATO.

4. Security beyond the eastern flank is unlikely to be guaranteed by either the EU or NATO, at least in the short and medium term

Both NATO and the EU are making critical contributions to Ukraine’s ability to resist Russia’s aggression and to defending the Euro-Atlantic security space. When the guns eventually fall silent, the EU will have a vital role to play in Ukraine’s economic reconstruction, while the security partnership between Ukraine and NATO will be a key part of the country’s ability to mount effective deterrence and defence against Russia. At the same time, the war has highlighted that there are formidable obstacles to Ukraine and other states neighbouring Russia becoming members of either organisation. Crucially, from the start of the war, the US has been clear that its forces will not directly fight those of Russia. Given the likelihood that future relations between Russia and Ukraine will remain hostile, even following a potential end of the hot war, the prospects of Washington committing to a NATO Article 5 relationship with Ukraine, including extending its nuclear deterrence across the country, seem remote. Given the centrality of the US to European security, without Washington’s assent, there is little prospect of NATO taking in additional Eastern European states. Without the security guarantee of the US, EU enlargement to include Ukraine as a member also seems unrealistic, as the Union would be unable to defend the country against Russian spoilers or military action.

5. There is a growing interdependence between European and international security

The Ukraine war is an international conflict, not just a European one. Russia has secured supplies and support from Iran, North Korea, China and some of its post-Soviet neighbours, and has looked to nonaligned countries in Latin America, Africa and Asia for diplomatic cover for its actions. Ukraine’s transatlantic partners have forged ties with Australia, Japan, South Korea, Taiwan and others over sanctions and weapons supplies, and have endeavoured to ensure that swing states, such as India and Turkey, are onside as much as possible. While major conflagrations in Europe in the 20th century drew in the rest of the world, reflecting Europe’s then-centrality to global security, the Ukraine war has highlighted that economic, military-industrial, diplomatic and military power has diffused around the globe. Europe now needs the rest of the world to contain Russia effectively, but is currently struggling to achieve this. With the debate about how to manage the challenge posed by China rising rapidly in Europe, European states will increasingly have to redefine traditional ideas of European security to take account of wider security and military developments, notably in the Indo-Pacific.

Europe’s Emerging Security Order

The concept of European security – uniting Western Europe, the US and Canada – was a creation of the Cold War years as Europe became the epicentre of the global confrontation with the Soviet Union. Following the collapse of the Soviet order, an expansive idea of European security incorporating a region from Vancouver to Vladivostok emerged. The war in Ukraine highlights that a new European security order is emerging to replace previous concepts, but has yet to be fully defined.

The war has seen a shift in the centre of Europe’s geopolitical gravity to the Northern and Central Europeans, with their deep-rooted transatlantic orientations and often operating in new groupings. Many of these countries, notably Ukraine and Poland, are building large land-warfare capabilities that will further anchor European security in this area. Much of the future European security agenda will pivot around the defence and security of Ukraine. This shift is likely to ensure that Europe’s future strategic focus will be on building security against, and no longer with, Russia.

The UK needs to be clear that European security is evolving, and that the existing European security architecture does not align with the emerging security reality

At the same time, the war indicates that Europe’s key security challenges increasingly lie outside the borders of the EU and NATO, at a time when the US security commitment and resources that underpin the reach of those organisations is unlikely to be extended deep into Eurasia and, indeed, when the US is increasingly being drawn to Asia and the challenge of China. This is taking place when European security is increasingly no longer solely about Europe and requires policies that extend far beyond the continent.

The current institutional architecture of European security, forged in the Cold War, does not fit with contemporary security challenges, while the post-Cold War policies of European integration and enlargement are unlikely to be able to offer answers – at least in the short to medium term – to the leading current threats. This suggests that there will be real limits to the reach of Euro-Atlantic institutions beyond the eastern flank of NATO, and that new security arrangements which go beyond NATO and the EU and the limits of US commitments will need to be established to manage regional threats and the global dimensions of European security.

The UK and the New European Security

The UK has demonstrated its centrality to European security in terms of its early recognition of the strategic threat that Russia posed and its support for Ukraine. As the UK looks to define its post-Brexit international role, rebuilding ties with European allies will be crucial. It is clearly right to foster a new relationship on security with the EU and to consolidate the UK commitment to NATO. At the same time, the UK needs to be clear that European security is evolving, and that the existing European security architecture does not align with the emerging security reality. The recent establishment of the European Political Community with its broad membership is an indication of this.

The UK and Europe face a moment as significant as the early 1990s and the fall of the Communist bloc. While the Euro-Atlantic institutions will remain important pillars of European security, including supporting Ukraine, new security arrangements capable of containing Russia and addressing the challenges that have emerged in Eastern Europe and the Black Sea, as well as responding to the growing importance to Europe of Indo-Pacific security, will need to be created. Much of this agenda is likely to be met through networks of ad-hoc and coalition-of-the-willing security partnerships and the creation of new security communities, which may involve the US but can also be centred around groups of leading European countries.

A defining moment will be when the fighting eventually stops in Ukraine. The end of the war will not just be about setting the terms of the Russia–Ukraine relationship; it will be about the new balance of power across Europe. This will also be a moment when there are likely to be widely diverging views on the future of the continent’s security, how to manage Russia, and even the very concept of European security. The UK is already well positioned to be a leader through its commitment to Ukraine, its role in the Joint Expeditionary Force, its significant engagement and partnerships in the Black Sea and northern Europe, and its new alliances in the Indo-Pacific (notably AUKUS and its developing defence ties with Japan). With security across the continent in transformation, the central lesson of the war in Ukraine is that now is the time for the UK to look beyond recent domestic political battles over Europe and to take a leading position in setting out a vision for a new European security order.

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

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Dr Neil Melvin

Director, International Security

International Security

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