NATO is meeting on 10 and 11 July in the Lithuanian capital, Vilnius.
The 31 heads of State and government attending will focus on support for Ukraine. The unity of the organisation has made it possible to defeat Russian violations of treaties and the international order.
However, the world's most powerful military alliance alone would not have been enough to oppose these transgressions. Aid from the European Union has helped the Ukrainian state to continue to function and its people to survive the conflict. This aid is in excess of €75 billion, equal to that given by the United States.
Never before has the complementarity between the two organisations been so clear.
Europeans do not currently defend Europe; NATO does.
Without NATO, the Russian army would today be on the borders of the European Union, which it would not fail to threaten.
And the stability and peace of the continent largely depend on the outcome of Russia's aggression. To dissuade it, NATO must offer Ukraine the prospect of membership and tangible guarantees of support.
Without the European Union, this time unanimous, courageous Ukraine would probably not have resisted so proudly.
It is now up to the two organisations to write a clearer future.
If Europeans want to acquire autonomy and guarantee their security, they must, as their allies have long been demanding, invest more massively in their defence, and above all, do so together. They must not just invest in conventional weapons; they must also consider whether they themselves have the capacity to deter a potential nuclear-armed aggressor. This will not weaken their alliance with America, which looks mainly to the Pacific.
The Americans must also play the game of a Europe that is gradually trying to take matters into its own hands, without using their massive dominance of NATO to sell their equipment to the detriment of the European defence industry, which needs to be strengthened. They know they can count on their European allies in the democratic camp, and no one imagines that a conflict involving America, for example in Asia, would fail to provoke the commitment of Europeans at its side.
This complementarity must now mature to combine credible defensive military forces with a more offensive Europe in diplomatic and political terms. The wars in Georgia and Ukraine might have been avoided if Europe had been able to dissuade Russia. In the wake of Russia's war of aggression in Ukraine, Europeans are likely to have to prepare for a new era.