Though few at Nato would admit it, in his first four years as US President, Donald Trump had more impact on the security alliance than his immediate predecessors, Obama and Bush, put together. To understand the future Trump-Nato relationship, one should look to the past.

The most obvious Nato success of the first Trump administration was to get European members of Nato to begin the long process of increasing expenditures to meet the Nato minimum goal of spending 2% of GDP on defence. This goal in some form or another had existed since 1999. All Nato members had repeatedly affirmed it. The Bush and Obama administrations had even threatened harsh consequences for their allies in failing to meet it. Only Trump succeeded in getting the Europeans to take the goal seriously. When Trump came to power, only four countries in Nato Europe met the 2% guideline. Now it is 23, out of 32 allies. Of course, Putin’s aggression towards Ukraine played a major part. But Trump’s pressure was decisive. In effect, he got his way by coercion, virtually threatening US withdrawal from Nato should the Europeans continue to ignore the 2% guideline that they had repeatedly affirmed. 

Trump’s impact was wider and deeper than getting Europeans to spend more on defence. In 2019, at a Nato Summit in London, he pressurised a reluctant alliance to admit for the first time that China could be a challenge ‘that we need to address together as an Alliance’, according to the London declaration. The language was modest, and seemingly obvious and innocuous. Its significance was great. At Trump’s insistence, the Europeans’ hitherto firm resistance to bringing China into Nato’s ambit of concern was broken.