When faced with foreign security threats of systemic proportions, such as from a nuclear military power like Russia, EU defense can only be effective in the transatlantic alliance framework. As long as Russia constitutes the biggest security threat for a number of EU member states, NATO will remain the main security provider in Europe.
However, European strategic autonomy is not over, and should not be over. It still makes sense to have a developed EU pillar within the Euro-Atlantic alliance framework, with complementarity, avoiding duplication. Strategic autonomy is desirable in terms of Europe developing the defense capabilities to reduce dependence on the United States, something U.S. administrations have also been keen to promote. A European defense industry through common procurement is also a priority.
European strategic autonomy is important when it comes to security challenges deemed crucial for the EU but less so for NATO, for example in Africa or the East Mediterranean. The EU should be able to define its own interests and collective objectives, and to enlist sufficient instruments to pursue them. And sometimes interests and priorities may diverge between the EU and NATO. The motto should be: together when possible, alone when necessary.