As the dust from NATO’s summit in May settles, Brussels gears up for a European Council meeting this week. Europe’s leaders are reflecting on a change in the political mood after President Trump’s visit and seem determined to show they can strengthen the continent’s security.

But how? Given the political tensions in the Euro-Atlantic area, this European Council should not miss the opportunity to reinforce the institutional backbone of Europe’s security through a closer EU-NATO relationship.

Last year, the EU-NATO Joint Declaration set out areas in which the two institutions should cooperate more closely. Previously, despite sharing 22 member states in common, cooperation on security between the EU and NATO had been stymied by political obstacles and the lack of a clear mandate. Since the Joint Declaration, international staffs at NATO and the EU have worked to implement 42 action points in seven key areas: countering hybrid threats, operational cooperation, exercises, cyber security and defence, defence capabilities, defence industry and research, and defence and security capacity building in third countries.

Significant progress has been made, especially in improving communication and coordination between the two institutions. In the process, transparency, trust and evidence of the benefits of cooperation between the EU, NATO and their respective member states has grown.

This progress is all the more noteworthy for having been achieved amidst new political rifts – on top of the long-standing blocks on good EU-NATO working placed by EU member Cyprus and NATO member Turkey. Following Turkey’s constitutional referendum, the EU’s relations with Turkey have deteriorated. After Austria brought EU accession talks with Turkey to a halt, President Erdogan put into question NATO collaboration with non-NATO partners like Austria. Worsening relations between Turkey and Germany are unlikely to help. And President Trump’s attitude towards America’s Allies is making some EU member states uneasy about the political risks of a relationship with NATO.

In the circumstances, it would be tempting for EU leaders this week to think that placing more of their countries’ security in EU hands and giving up on the frustrations of working with non-EU Allies in NATO would be the way to go.

Yet transatlantic unity and a strong EU-NATO relationship remain essential for the future of European security and defence. Closer EU-NATO relations offer a more sustainable and inclusive vision of Europe’s contribution to defence than the two overlapping institutions each going it alone. Closer relations would help increase efficiency and optimise defence spending. More importantly still, they could deliver a more coherent defence planning process, greater sustainability of operations and stronger relationships with partner countries.

Earlier this month, the EU Commission set out several possible visions for future European defence. In a loose integration scenario the EU would continue to cooperate with NATO in some areas, under the current mandate of the Joint Declaration. In the most integrated scenario, the Commission envisions the EU and NATO as mutually reinforcing partners sharing the responsibility for the defence of Europe. This is one sign of new momentum for European defence integration, the end goal of which could be much greater EU-NATO synergy.

Member states committed to closer collaboration between the EU and NATO should respond to political differences in Europe and across the Atlantic with a clear and ambitious message of collaboration for the two institutions.

In May 2017 the European Leadership Network published our in-depth report examining the inter-institutional relationship and the progress achieved so far. We argued that EU Member States and NATO Allies ought to be more ambitious about the relationship between the two institutions, building on the new dynamic of cooperation created so far. We identified key actions required to improve and facilitate cooperation. These recommendations were endorsed in a group statement by 62 distinguished European statesmen and women.

Ahead of the European Council meeting this Thursday, European leaders could borrow from these recommendations and consider five practical measures that would make a real difference to Europe’s security:

• Start with a discussion on additional resources and staffing for NATO and the EU dedicated to improving their institutional cooperation.

• Follow through by expanding the EU’s capacity and investing in secure communications, security clearance for more staff and training them to work with classified information.

• Encourage closer coordination between EU and NATO permanent representations in Brussels, and in relevant partner countries.

• Explore the creation of additional security Centres of Excellence, steered by both institutions.

• Support EU-NATO collaboration in partner countries. Consider on-the-ground cooperation to bridge institutional obstacles.

After the EU Foreign Affairs Council on Monday, ministers stressed the importance and positive progress of current EU-NATO cooperation. The European Council meeting on Thursday is an opportunity to affirm this reality and turn words into deeds.