Yet, through its many ups and downs, the relationship has proved resilient. Trade flows between the eu and the United States remain the world’s biggest, worth more than $3bn a day. Shared democratic values, though wobbly in places, are a force for freedom. And, underpinning everything, the alliance provides stability in the face of a variety of threats, from terrorism to an aggressive Russia, that have given the alliance a new salience.
At the heart of this security partnership is nato. By reaching its 70th birthday the alliance stands out as a survivor—in the past five centuries the average lifespan for collective-defence alliances is just 15 years. Even as European leaders wonder how long they can rely on America, the relationship on the ground is thriving. As our special report this week explains, this is thanks to nato’s ability to change. No one imagined that the alliance’s Article 5 mutual-defence pledge would be invoked for the first, and so far only, time in response to a terrorist attack on America, in September 2001, or that Estonians, Latvians and Poles would be among nato members to suffer casualties in Afghanistan. Since 2014 the allies have responded vigorously to Russia’s annexation of Ukraine. They have increased defence spending, moved multinational battlegroups into the Baltic states and Poland, set ambitious targets for military readiness and conducted their biggest exercises since the cold war.