Ukraine is on the path to join both the EU and NATO, while defending itself – and Europe – against Russia’s brutal aggression. It is essential for Ukraine’s future that the two accession processes proceed hand in hand, complementing each other. EU-NATO complementarity is needed to provide Ukraine with credible security guarantees, strong international support to reconstruction as well as a well-functioning judiciary and the rule of law.
Complementarity has been a much-used concept to characterise the division of roles between the European Union (EU) and The North Atlantic Treaty Organization (NATO) in securing Europe. There are three important aspects of EU-NATO complementarity with regard to Western support to Ukraine.
First, when it comes to security guarantees, a core division of tasks between the EU and NATO remains: NATO is the only organisation capable of providing credible security guarantees and taking care of collective defence of its members. This is why it was so important for Ukraine to receive a clear promise of future NATO membership at the Vilnius Summit in July this year. The indispensable role of NATO for European security has been underscored by the return of full-scale war to Europe.