A renewed sense of urgency over European defence has come only after a cumulative series of strategic shocks. The European powers have long resisted ^[1] supranational defence institutions, instead depending heavily on NATO and the US. Prior to 1989, Western European and US strategic interests converged as the trans-Atlantic powers faced a hostile Soviet Union. After the Cold War, the Europeans failed ^[2] to assume responsibility for the peace and security of their own continent. Can they now?

Europe’s buoyant post–Cold War mood was shattered ^[3] by the brutal Bosnian War ^[4] (1992–1995), Russia’s employment of force in Georgia (1991–1993), and then war in Kosovo ^[5] (1998–1999). Those shocks catalysed an intense turn-of-the-century debate ^[6] over Europe’s capacity to manage its own security affairs. Impotence ^[7] over Kosovo, in particular, highlighted the problem ^[8], though little actual progress occurred as a result.

The debate was reinvigorated by Russia’s violations of territorial sovereignty ^[9] in Georgia (2008) and in Ukraine, and the occupation and annexation of Crimea (2014). It was exacerbated by mass migration from Africa and the Middle East, domestic extremist violence, and the Brexit referendum (2016). President Donald Trump’s ^[10] ambiguity about the US commitment to NATO and policy cleavages over the Paris climate agreement and the Iran nuclear deal helped precipitate the latest movement on European defence.

Even before Trump’s election, analysts ^[11] considered that ‘the ability of the EU to collectively ensure its security and defence is in serious doubt’ and that ‘security and defence have become the new front lines of the European project’. The EU’s 2016 global strategy ^[12] stated that ‘investment in security and defence is a matter of urgency’, arguing that ‘full spectrum defence capabilities are necessary to respond to external crises, [to] build our partners’ capacities, and to guarantee Europe’s safety’. It stressed that ‘capabilities should be developed with maximum interoperability’.

The 2007 Lisbon Treaty ^[13] sought to ‘enable tangible progress on the level of investment expenditure on defence equipment, collaborative capability development goals and the availability of deployable defence capabilities for combined missions and operations acknowledging the single set of forces principle’. Permanent structured cooperation ^[14] (PeSCO) was the intended vehicle.

Only ‘limited progress ^[15]’ has been made on PeSCO. Participation in PeSCO is restricted to EU member states that satisfy the criteria in Protocol 10 to the Lisbon Treaty. Contrary to the EU’s norm of unanimity, the European Council (EC) decided to require a qualified majority vote on PeSCO-related issues to avoid matters being blocked by dissenting members.

A joint notification ^[16] on PeSCO was presented to the EC by 23 member states in November 2017. It set out 20 commitments, including increasing defence budgets to 2% of GDP in real terms, increasing defence investment expenditure to 20% of total defence spending, engaging more in joint and collaborative strategic defence capabilities projects, developing the interoperability of their forces, optimising multinational structures, and using the European Defence Agency (EDA) as the forum for joint capability development.

PeSCO will be closely tied to the new coordinated annual review on defence ^[17], an EDA initiative that systematically monitors national defence spending plans, and the European Defence Fund ^[18], which is currently being developed. The initial PeSCO projects ^[19] will be put to the EC for endorsement in early 2018 and will address ‘training, capability development and operational readiness’.

As the impetus towards greater cooperation, coordination and interoperability on defence builds, the countervailing forces are asserting themselves. The fate of achieving effective defence policy integration may depend on the growing reaction to European integration in general in other policy domains. European voters are increasingly concerned that loss of sovereignty and the dilution of national culture will result in the politicisation ^[20] of European integration. Brexit ^[21] is the exemplar of that phenomenon.

Moreover, national defence and the exercise of sovereign rights are integral to nation-states. The 2017 French strategic review ^[22] strongly emphasised this, insisting that ‘maintaining the model of a full-spectrum and balanced military is critical for France’s national independence, strategic autonomy and freedom of action’. In the economic sphere, the review declared that ‘pursuing a high level of ambition in the manufacturing and technology fields is a matter of sovereignty and a pillar of our strategic autonomy’. That stands in contrast to President Emmanuel Macron’s views ^[23] on national sovereignty and EU integration in general.

The French review’s nod towards ‘permanent structured cooperation and the European Defence Fund’ belies the tension between strategic autonomy and the meaningful integration of the EU’s most powerful ^[24] military into a supranational institution. Similarly, Italy, another major European power, speaks in its 2015 white paper ^[25] of focusing ‘on those geographical areas that are a priority for national interests’ and ‘pushing into the background other crises’. Germany’s Social Democrats ^[26]oppose increasing defence expenditure to 2% and their inclusion in a new coalition government would pose problems for PeSCO.

Achieving effective interoperability, capability development and readiness—and unity of command—across 23 sovereign nations will be a herculean task. The historical legacy of dissimilar national approaches to capability will need to be addressed, and inevitably diverging national interests will arise based on straightforward geography. In Eastern Europe, the Russian threat looms large, while nations facing the Mediterranean will concentrate more on the Middle East chaos and the ungovernable spaces of North Africa. Issues of domestic politics, especially the prevalence of Euroscepticism, and the effects of strategic culture ^[27] will also need to be overcome.

That new life has been injected into the issue of European defence is a symptom and recognition of the tectonic shifts taking place in international power relationships. Still, even when confronted with new and serious strategic challenges, there’s no guarantee that the national interests of its members will aggregate into a set of common EU defence interests. The engagement in PeSCO is encouraging, but there’s a long way to go before Europe can expect to effectively defend Europe.