Understanding the revival of the European Defence Community: a historical perspective

Europe has endured two devastating World Wars, leading a group of countries to pursue cooperation and integration as a means to achieve peace and security.

Since then, the European Union (EU) and its predecessors have been renowned as a soft power, promoting peace through economic integration, a role acknowledged by the Nobel Peace Prize in 2012. How, then, can we comprehend Europe's current need to ramp-up its defense capabilities 80 years after WWII?

This history is not one of linear progress but rather a cycle of acceleration and stagnation, often influenced by external shocks. Current discussions about European defence are not new, and while past debates don’t need to be reinvented, the choices made today will likely differ.

It may come as a surprise that in 1999, EU Member States agreed to be able to deploy up to 60,000 troops within 60 days and sustain them for at least one year. However, this eventually resulted in the more modest capability of two EU battle groups (3,000 troops in total) on standby as a rapid reaction force. So let’s take a step back and look how it all started.

Coat of arms EU Military Staff

The Early Years of European Defence Cooperation

During the first decade after World War II, multiple defence agreements were established in a short period. A key debate was whether these defence structures should be centralized (supranational/federal) or intergovernmental (unionist).

• 1947: Dunkirk Treaty between the UK and France for mutual military assistance.

• 1948: Brussels Treaty: Agreement between the UK, France, and the Benelux countries on collective self-defence, socio-economic, and cultural cooperation—laying the foundation for NATO and the Western European Union (WEU).

• 1949: Establishment of NATO.

• 1950: The ‘Pleven Plan’ proposed a European Defence Community (EDC).

• 1952: EDC Treaty signed, envisioning an integrated army with a common budget, procurement, and armaments industry.

• 1954: The French parliament rejected the EDC Treaty.

• 1954: As an alternative, the Western European Union (WEU) was established under a modified Brussels Treaty. Members that followed the founding partners were Italy and (West) Germany. It took till the 90s for Spain, Portugal and Greece to become full members. Other European states became involved in the 90s as well.  

  
  

The Cold War and the WEU’s sleeping mode

During the Cold War, the WEU was largely inactive, as NATO, under U.S. leadership, dominated military affairs in opposition to the Warsaw Pact. However, by the mid-1980s, as the Soviet Union (called ‘the Empire of Evil’ by US president Ronald Reagan) embraced glasnost and perestroika, including arms reductions, the WEU saw a revival. European states began reconsidering future security and defence frameworks.

Article V of the WEU Treaty guaranteed collective defence:

“If any of the High Contracting Parties should be the object of an armed attack in Europe, the other High Contracting Parties will, in accordance with the provisions of Article 51 of the Charter of the United Nations, afford the Party so attacked all the military and other aid and assistance in their power.”

The WEU played a role in coordinating its members’ military presence, particularly in the Middle East. Between 1987 and 1991, it conducted military operations in Iraq and the Persian Gulf, including minesweeping during the Iran–Iraq War and the Gulf War, ensuring the free movement of vessels and enforcing the UN arms embargo on Iraq.

With the Petersberg Declaration, the WEU’s mandate expanded to include peacekeeping, humanitarian, and rescue operations.

The EU’s Role in Defence Integration

The Treaty of Maastricht (1992) designated the WEU as a potential defence component of NATO, emphasizing the need for a European Security and Defence Identity. However, when conflicts erupted in former Yugoslavia in the 1990s, the EU’s Common Foreign and Security Policy proved inadequate for military operations. To address these shortcomings, EU Member States explored ways to provide the EU with operational capacities, either by developing European resources or utilizing NATO.

The Treaty of Amsterdam (1997) laid the groundwork by integrating the Petersberg Tasks into the EU framework. It also established the European Security and Defence Policy (ESDP) and created the role of High Representative for Common Foreign and Security Policy.

Military structures from the WEU incorporated into the EU include: European Union Military Staff (EUMS), European Union Military Committee (EUMC), EU Satellite Centre (SatCen), Crisis Response Mechanisms and the EU Institute for Security Studies.

The Revival of European Defence Cooperation

Two key summits in 1998 catalyzed further defence integration:

• The Franco-German Potsdam Summit: Committed to advancing the Common Foreign and Security Policy, including European Defence Policy, with a focus on crisis prevention and management, particularly in Yugoslavia and the Middle East.

• The British-French Summit in St. Malo: Stated a more ambitious goal:

“The European Union needs to be in a position to play its full role on the international stage. This means making a reality of the Treaty of Amsterdam, (…) To this end, the Union must have the capacity for autonomous action, backed up by credible military forces, the means to decide to use them, and a readiness to do so, in order to respond to international crises. Europe needs strengthened armed forces that can react rapidly to the new risks, and which are supported by a strong and competitive European defence industry and technology.”

The ESDP was formally established under the Treaty of Amsterdam (1997) and further developed under the Treaty of Nice (2001). It was later integrated into the Common Security and Defence Policy (CSDP) with the Treaty of Lisbon (2007), which entered into force in 2009.

A returning discussion is if the EU should only expand joint cooperation with NATO but avoid doubling structures and capabilities, i.e. no duplication, or that the EU should work towards more autonomy. The US has been in favour of the EU spending more on defence, especially when buying American, but under US leadership, not for the EU to develop a fully autonomous military pillar within the EU. An enduring conceptual framework within European defence discourse is captured by the so-called “3Ds”: Decoupling, Discrimination, and Duplication. These concerns were coined in the late 1990s by then-U.S. Secretary of State Madeleine Albright and remain relevant today.

• Decoupling refers to the risk of weakening the transatlantic link, whereby EU defence efforts might drift away from NATO structures.

• Discrimination points to the potential exclusion of non-EU NATO allies, particularly the U.S. and Turkey, from decision-making or participation in European defence matters.

• Duplication expresses concern about the EU unnecessarily replicating NATO’s military planning and capabilities.

While the EU has since taken steps to reassure NATO allies—stressing complementarity and transparency—the 3Ds continue to shape debates around strategic autonomy and the appropriate balance between EU-led defence initiatives and NATO cohesion

Developments in CSDP Between 2009 and 2020

After the Treaty of Lisbon (2007) fully integrated the Common Security and Defence Policy (CSDP) into the EU framework, notable advancements occurred from 2009 to 2020. In reaction to rising geopolitical instability, the EU bolstered its security and defence collaboration through initiatives like Permanent Structured Cooperation (PESCO) in 2017. PESCO allowed participating EU Member States to work together on military projects, improving operational readiness and interoperability. Furthermore, the establishment of the European Defence Fund (EDF) in 2017 was designed to enhance investment in defence research and development. During this period, the EU also initiated military training missions in Mali, the Central African Republic, and Somalia, highlighting an increased commitment to crisis management beyond Europe. Additionally, there was a closer NATO-EU cooperation, especially in cyber defence, hybrid threats, and military mobility, emphasizing the EU's evolving role as a security actor.

Recent Developments in European Defence Policy (2020–2025)

In the wake of escalating geopolitical tensions, particularly Russia's full-scale invasion of Ukraine, the EU has significantly accelerated its defence integration. Defence spending among EU countries rose by over 30% between 2021 and 2024, reaching an estimated €326 billion—equivalent to 1.9% of EU GDP.

But the biggest catalyst moving the EU towards being a military actor is an US administration threatening other NATO members, undermining collective defence and disregarding international law.

In response to growing security threats,  the European Commission launched the ReArm Europe Plan/Readiness 2030 in 2025, enabling EU countries to allocate up to 1.5% of their GDP to defence without fiscal penalties. The plan includes a €150 billion loan scheme for joint military procurement, which is also open to Ukraine and other European partners.

Additionally, legislative initiatives such as the European Defence Industry Reinforcement through Common Procurement Act (EDIRPA) and the Act in Support of Ammunition Production have been introduced to address critical gaps in military stockpiles and enhance the EU’s industrial base. The European Defence Industry Programme (2025–2027) further aims to strengthen the EU's long-term strategic defence capabilities. The European Parliament has strongly endorsed these efforts, calling for innovative funding mechanisms and greater autonomy in European security policy.

Conclusion

The European defence landscape has undergone cycles of integration and hesitation, often dictated by global events and shifting security challenges. While past initiatives like the European Defence Community failed, the EU has gradually  built its defence capabilities through treaties and cooperation frameworks.

As discussions continue, the lessons of history show us that the European defence cooperation continues an evolving and dynamic reality, even if progress may not always be in an upwards linear direction. As an economic block the EU is a global power, it is not in the interest of other powers to see a serious rise of EU military strength. However, Chinese spy & cyber acts, Russian military threats & sabotage and the US's increasingly erratic behaviour gives the EU a push towards centralised military structures that otherwise would have stayed underdeveloped. In order to stay relevant in an increasingly multipolar world, the only way to stay relevant for EU member states is to build closer cooperation and operate as one-block. For the European peoples, European nation states must allow more centralised decision making.

‘There is a remedy which would in a few years make all Europe free and happy. It is to re-create the European family, or as much of it as we can, and to provide it with a structure under which it can dwell in peace, safety and in freedom. We must build a kind of United States of Europe.’ Winston Churchill, Speech held at the University of Zurich (1946)

This blog does not seek to be comprehensive but aims to provide context on today's European defense movements, considering the historical events that have shaped the continuously evolving EU defense narrative. The field is rapidly changing, and new challenges will influence its path in the coming years.