History of the Common Security and Defence Policy

The post-war period saw several short-lived or ill-fated initiatives for European defence integration intended to protect against potential Soviet or German aggression: The Western Union and the proposed European Defence Community were respectively cannibalised by the North Atlantic Treaty Organisation (NATO) and rejected by the French Parliament. The largely dormant Western European Union (WEU) succeeded the Western Union's remainder in 1954. In 1970 the European Political Cooperation (EPC) brought about the European Communities' initial foreign policy coordination, which in turn was replaced by the newly founded EU's CFSP pillar in 1993. The WEU was reactivated in 1984 and given new tasks, and in 1996 NATO agreed to let it develop a European Security and Defence Identity (ESDI).^[1] The 1998 St. Malo declaration signalled that the traditionally hesitant United Kingdom was prepared to provide the EU with autonomous defence structures.^[2] This facilitated the transformation of the ESDI into the European Security and Defence Policy (ESDP) in 1999, when it was transferred to the EU. In 2003 the EU deployed its first CSDP missions, and adopted the European Security Strategy identifying common threats and objectives. In 2009, the Treaty of Lisbon introduced the present name, CSDP, while establishing the EEAS, the mutual defence clause and enabling a subset of member states to pursue defence integration within PESCO. In 2011 the WEU, whose tasks had been transferred to the EU, was dissolved. In 2016 a new security strategy was introduced, which along with the Russian annexation of Crimea, the scheduled British withdrawal from the EU and the election of Trump as US President have given the CSDP a new impetus.

The Treaty of Dunkirk was in essence succeeded in March 1948 by Article 4 of the Treaty of Brussels, to which the Benelux countries were also party, established in September the same year the Western Union (WU), also referred to as the Brussels Treaty Organisation (BTO), with an allied European command structure under British Field Marshal Montgomery. West Germany had been occupied by Allied forces and lacked its own means of defense. The military arm of the WU was referred to as the Western Union Defence Organisation (WUDO). The overall command structure was patterned after the wartime Supreme Headquarters Allied Expeditionary Force (SHAEF), which included a joint planning staff.^[3] WUDO could also be compared with the defence organisation in the United Kingdom.


When the division of Europe into two opposing camps became considered unavoidable, the threat of the USSR became much more important than the threat of German rearmament. Western Europe, therefore, sought a new mutual defence pact involving the United States, a powerful military force for such an alliance. The United States, concerned with containing the influence of the USSR, was responsive. Secret meetings began by the end of March 1949 between American, Canadian and British officials to initiate the negotiations that led to the signing of the North Atlantic Treaty on 4 April 1949 in Washington, DC. The need to back up the commitments of the North Atlantic Treaty with appropriate political and military structures led to the creation of the North Atlantic Treaty Organisation (NATO). In December 1950, with the appointment of General Eisenhower as the first Supreme Allied Commander Europe (SACEUR), the members of the Treaty of Brussels decided to transfer the headquarters, personnel, and plans of the Western Union Defence Organisation (WUDO) to NATO.^[4] NATO's Supreme Headquarters Allied Powers Europe (SHAPE) took over responsibility for the defence of Western Europe, while the physical headquarters in Fontainebleau were transformed into NATO's Headquarters, Allied Forces Central Europe (AFCENT).^[5][6][7][8]


The establishment of NATO and the International Authority for the Ruhr, along with the signing of a succession of treaties establishing Organisation for European Economic Cooperation (April 1948), the Council of Europe (May 1949) and the European Coal and Steel Community (April 1951), left the Western Union and its founding Treaty of Brussels devoid of much of their prominence. By 1951, the fear of possible Soviet aggression in Europe, as well as the Pleven plan, proposed in 1950 by then French Prime Minister René Pleven in response to the American call for the rearmament of West Germany, led France, West Germany, Italy and the Benelux – the Inner six of European integration – to propose a scheme that was similar in nature to the ECSC but concerned defence; the European Defense Community (EDC). The EDC would have consisted of a pan-European military divided into national components, with a common budget, common institutions, common arms and centralised procurement. At the time, this was favoured over admitting Germany to NATO. The General Treaty (German: Deutschlandvertrag) of 1952 formally named the EDC as a prerequisite of the end of Allied occupation of Germany. The EDC founding treaty did not enter into force, however, as it failed to obtain approval for ratification on 30 August 1954 in the French National Assembly where Gaullists feared for national sovereignty and Communists opposed a European military consolidation that could rival the Soviet Union.

From the late 1970s onwards, efforts were made to add a security dimension to the EC's EPC. Opposition to these efforts from Denmark, Greece and Ireland led the remaining EC countries – all WEU members – to reactivate the WEU by means of the 1984 Rome Declaration.^[12] Following the European Communities' 1986 Single European Act, which codified the EPC in EU law contained little of substance on EC defence integration, the WEU member states adopted the Platform on European Security Interests, which emphasised the need for intra-European defence integration and strengthening of NATO's European pillar.


In 1992, the WEU adopted the Petersberg Declaration, defining the so-called Petersberg tasks designed to cope with the possible destabilising of Eastern Europe. The WEU itself had no standing army but depended on cooperation between its members. Its tasks ranged from the most modest to the most robust, and included Humanitarian, rescue and peacekeeping tasks as well as tasks for combat forces in crisis management, including peacemaking.^[14]


Upon the entry into force of the Maastricht Treaty in 1993, the European Union was established, consisting of three pillars, of which the first was the European Communities, one was the Common Foreign and Security Policy (CFSP) – a replacement of the European Communities' EPC – and the last was the Justice and Home Affairs (JHA). The CFSP pillar became a natural basis for a further deepening of EU defence policy cooperation.


At the 1996 NATO ministerial meeting in Berlin, it was agreed that the WEU would oversee the creation of a European Security and Defence Identity (ESDI) within NATO structures.^[15] The ESDI was intended as a European 'pillar' within NATO, partly to allow European countries to act militarily where NATO wished not to, and partly to alleviate the United States' financial burden of maintaining military bases in Europe, which it had done since the Cold War. The Berlin agreement allowed European countries (through the WEU) to use NATO assets if it so wished.

The mutual defence clause, Article 42.7, was invoked for the first time in November 2015 following the terrorist attacks in Paris, which were described by French President François Hollande as an attack against Europe as a whole.^[24][25]


In 2016 HR/VP Federica Mogherini drew up a new security strategy, the European Union Global Strategy, which along with the Russian annexation of Crimea, the scheduled British withdrawal from the EU and the election of Donald Trump as US President have given the CSDP a new impetus.


This has given rise to a number of initiatives:


The MPCC is a part of the External Action Service's Military Staff (EUMS) that constitutes the EU's first permanent operational headquarters. The Director General of the EUMS also serves as Director of the MPCC – exercising command and control over the operations within the MPCC's remit.


In wake of the Russian invasion of Ukraine in February 2022, the EU gave €500M in arms and aid from its European Peace Facility to the Ukrainian armed forces. This was the first time the EU financed the purchase and delivery of military equipment to a country under attack.^[26] On 1 June 2022, Denmark held a referendum on the lifting of the country's defense opt-out on EU security policies, that would enable Denmark to participate in the Common Security and Defense Policy.^[27] The referendum was passed with a majority of almost a 67% of voters in favour.^[28] In October 2022, the EU launched a military assistance mission in support of Ukraine, which entails training Ukrainian forces on EU soil.