This article belongs to the debate » The EU’s New Defence Policy
25 March 2019

The Historical Development of EU Defence Policy: Lessons for the Future?

Historical roots

The architecture of EU Defence Policy is strongly influenced by the historical conditions preceding its evolution. For more than thirty years, any military role of the European Communities had been out of the question. The only attempt to achieve military integration in Europe – the European Defence Community – had failed in 1954. Ultimately, under the conditions of the Cold War, European security could only be guaranteed by the United States and therefore had to be organized within an Atlantic framework. This led to a long-lasting split between military and political/economic integration in Europe. The European Communities remained strictly limited to the latter, while military integration was exclusively a matter of NATO. When the new European Union – more than thirty years after the Treaties of Rome – finally turned to the field of defence policy it was a latecomer. Therefore, any EU defence policy had to be integrated into the preexisting and highly sophisticated Euro-Atlantic security structures with NATO in the foreground.

Against this background there were specific objections which made the establishment of an EU defence policy a highly controversial project: the clear preference of some Member States, in particular of the UK, for keeping the defence dimension within the Atlantic Alliance; the undeniable difficulty to give the EU a defence role without damaging the integrity of NATO and without costly duplications of NATO’s defence structures; the general unwillingness to give up sovereignty in military issues; and the neutrality policy of some Member States (at the time: Ireland). Moreover, it was a fundamental shift from the deeply rooted tradition, perception and self-conception of the Communities, and then of the EU, as a purely “civilian power”.

That defence policy, against all odds, found its way into the Maastricht Treaty, had much to do with rifts within the Atlantic Alliance: European fears as to the reliability of the American security guarantee and quarrels about burden sharing. Moreover, there were interests at stake in strengthening the process of European integration in general. This led to a characteristic mixture of defence based motives and integration based motives behind EU defence policy.

The further development of EU defence policy can be divided in four stages:

  1. Introduction as a set of legal rules in the Maastricht Treaty (1992/93), based on the WEU as military arm of the EU. This stage remained largely theoretical.
  2. Actual launch of the European Security and Defence Policy (ESDP), triggered by the Balkans Crisis and the UK giving up its traditional opposition on the summit of St. Malo (1998/99). These years of almost revolutionary change saw the establishment of the EU as a defence player, bypassing the WEU, building its own politico-military institutions and operational capabilities.
  3. Stagnation since about 2005,following the failure of the Constitutional Treatyand thegreat financial crisis. The Treaty of Lisbon codified the essential achievements of the ESDP (now: Common Security and Defence Policy, CSDP) but added little new. Beyond that, CSDP lost political priority and got bogged down in daily routine and lack of resources.
  4. Revival with a number of fresh initiatives – notably the establishment of PESCO – as an attempt to induce a new dynamic to enhance the European military capabilities. Early signals for such a new trend can be traced back to the European Council in December 2013 but it is only since 2017 that genuine policy steps have been taken in that direction.

Essential features of the CSDP-architecture

Four essential features and elements of the CSDP-architecture mirror the above-mentioned framework conditions:

  • Twofold dimension: CSDP consists of an operational dimension and a capability dimension. The operational dimension relates to the conduct of military operations under the auspices of the EU, including the establishment of the necessary institutional structures. The capability dimension deals with the development of military capabilities in the armed forces of the Member States by way of coordinated armaments policy and defence planning mechanisms. This capability dimension has been an integral part of the ESDP-project since St. Malo. It has the purpose of providing the EU, in the long run, with a more capable military instrument, but also of strengthening European defence in general.
  • Scenario crisis management: CSDP, in its operational dimension, has been designed for international crisis management, not for collective self defence against a direct armed attack (cf. Art. 42 para 1 TEU with its limitation to operations outside the EU territory). Although the Treaty of Lisbon has introduced a collective defence clause (Art. 42 para 7 TEU) this clause establishes merely a horizontal support obligation between the Member States. It does not provide for any military role of the EU in this context.
  • EU force structure: The EU does not have military forces of its own. CSDP is based on national armed forces of its Member States, including headquarters. National contingents are temporarily placed under EU operational control and made available for EU operations or – on a rotational basis – assigned to EU military formations (battlegroups). Moreover: There is no legal obligation for Member States to make such troop contributions. The EU force generation process is strictly based on voluntary contributions, fully respecting national sovereignty. These restrictions of the EU force structure are ultimately enshrined in the rather enigmatic distinction between the common defence policy and a (yet to be achieved) common defence in Art. 42 para 2 TEU.
  • Co-existence with NATO: CSDP has been designed to complement but not to replace NATO. Remarkably, the TEU explicitly confirms that CSDP is compatible with NATO policies and obligations (Art. 42 para 2 TEU). CSDP has been built on the principles of no de-linking (from the Atlantic Alliance) and no unnecessary duplications (of NATO structures and capabilities). This includes the “Berlin plus” option of falling back on NATO command structures (rather than installing separate EU headquarters) and the harmonization of defence planning processes. In operational terms, CSDP remains limited to small military missions; its trademark is civil-military cooperation in crisis management. By contrast, high intensity military operations and collective self-defence have been left to NATO. Ultimately, however, both organisations have to draw on the same single set of forces of their Member States.


There are, essentially, three reasons for the renewed CSDP-dynamic since 2017: The erratic stance of US foreign policy under President Trump with its rather hostile attitude towards NATO; the new confrontation with Russia since the Crimean Crisis in 2014; and the Brexit which has left CSDP without its main internal opponent. However, the impact of Brexit is ambivalent because it deprives the EU of a crucial military contributor. Thus, CSDP gains political momentum but loses military potential.

While these developments have increased the urgency of the CSDP project, they do not fundamentally change its underlying conditions. The traditional cornerstones that CSDP cannot replace NATO and that Member States will not give up their ultimate sovereignty in military affairs have remained unchallenged so far. Therefore it is very likely that CSDP will not radically change its face in the near future. Accordingly, the current new initiatives leave the established features of CSDP intact.

The bulk of the new initiatives – with PESCO at its heart – do not address the operational dimension of CSDP, i.e. the conduct of military operations. They are concerned with the capability dimension. In sum, they are a combination of renewed efforts to engage the notorious capability gap which becomes even more dramatic after Brexit. To achieve this goal they aim at establishing a system of deeper, more systematic and more closely monitored cooperation in armaments policy, defence planning and building efficient force structures. This goes along, in the framework of PESCO, with a certain legalization of commitments which, formerly, had been purely political.

A second tendency to be expected is a certain push for more independence from NATO (Europeanisation). Duplications which have been avoided so far will be no red lines anymore. A first small step has already been taken by upgrading the so-called Military Planning and Conduct Capability as strategic headquarters for a (small) executive military operation.

These are reasonable steps in the right direction. Efforts to tackle the notorious capability gap of the European armed forces are of primary importance. However, the impact of the new initiatives should not be overestimated. Their scope and ambition, as well as their legally binding force, is limited. Ultimately, everything depends on the continuous will of the Member States to fill them with life, to invest more in defence, and to give up some sovereign strongholds. Therefore, grand labels like a “European Defence Union” are rather misleading. In particular, there is no “European Army” in sight. For the foreseeable future, there is no return to the European Defence Community of the 1950s. A more realistic solution is a cooperative network of national armies, systematically using the concept of pooling & sharing. This is the path entered by the current initiatives. But for the time being, they are no more than fragmentary pieces of a puzzle which will require a great deal of time, efforts and resources if it is ever to be completed.

SUGGESTED CITATION  Graf von Kielmansegg, Sebastian: The Historical Development of EU Defence Policy: Lessons for the Future?, VerfBlog, 2019/3/25,, DOI: 10.17176/20190517-144428-0.

Leave A Comment


1. We welcome your comments but you do so as our guest. Please note that we will exercise our property rights to make sure that Verfassungsblog remains a safe and attractive place for everyone. Your comment will not appear immediately but will be moderated by us. Just as with posts, we make a choice. That means not all submitted comments will be published.

2. We expect comments to be matter-of-fact, on-topic and free of sarcasm, innuendo and ad personam arguments.

3. Racist, sexist and otherwise discriminatory comments will not be published.

4. Comments under pseudonym are allowed but a valid email address is obligatory. The use of more than one pseudonym is not allowed.

Explore posts related to this:
Common Security and Defence Policy, Defense, PESCO

Other posts about this region: