London — Since US President Donald Trump entered the White House in 2017, Nato summits have often proved diplomatically messy events. This year’s gathering in December in London could be the most volatile of the lot — taking place not just against the backdrop of unpredictable looming British and US elections, but now open questioning of the alliance’s future by French President Emmanuel Macron.

In an interview with The Economist published on Thursday, Macron said US strategic absence was leading to what he called Nato's "brain death”, also pointing to the US withdrawal from Syria as a sign that Washington was no longer interested in its allies or the world. European nations, he said, should "re-assess the reality of what Nato is”.

Exactly what he meant by that comment is very far from clear — in many respects, Nato has found new energy since Russia's annexation of Crimea in 2014, dramatically ratcheting up exercises and multinational deployments, particularly in Eastern Europe. What is apparent, however, is that France and to a lesser extent Germany would like to see Europe take more of its defence planning into its own hands, and do not necessarily see Nato as the only effective way of doing so.

That would worry Britain, much of the US security establishment as well as some small states, which would much rather see Nato remain as the basic framework for European defence, even with a much less active Washington. In the era of Trump and Brexit, however, they may simply not get much say.

Simple truth

The simple truth is that whoever wins the 2020 US presidential election, a growing contingent within both the Republican and Democratic parties want a much less forceful US presence, and are much less emotionally and intellectually attached to US's alliances. Whether or not they would honour Nato's Article 5 self-defence clause is hard to say — and that inevitably prompts Europe's most powerful states to look to build the structures that will serve them best.

In January, France and Germany signed an updated military co-operation treaty that guaranteed each would come to the other's defence and set out further steps to military co-operation, culminating in what would effectively be a joint army. That prompted angry tweets from Trump — which seems to have only cemented the Franco-German view that other, simpler structures that do not involve Washington are necessary.

On Thursday, German defence minister Annegret Kramp-Karrenbauer told an audience in Munich she believed France, Germany and Britain should formalise the tripartite "E3" group they have used when they wish to make statements on a topic on which they starkly disagree with Trump's US. First used as part of discussions with Iran going back to 2003, the E3 designation was used for several statements this summer, most recently calling for restraint after suspected Iranian drone and missile attacks on Saudi energy infrastructure in September.

Tying together the diplomatic resources of London, Paris and Berlin makes sense. Alone, none of the three can match the clout of the US or China, whereas together they make a much more formidable force. That doesn't mean, however, that significant differences of agreement won't often remain. That could become even more the case in an era of mounting populism, with the real if still remote possibility the far right could win presidential elections in France in 2022.

Common ground

Clearly, reaching common ground between E3 capitals will often be easier than navigating the multinational bureaucratic structures of either the EU or Nato. But that may itself ring alarm bells for smaller European nations, which value the way they are consulted and included in the architecture of both institutions. That is particularly important when it comes to mutual defence, when Nato's mechanisms in particular have long been designed to weld together different national militaries in the event of conflict in Europe or beyond.

As Nato member Turkey's intervention Syria and increasing ties to Moscow demonstrate, keeping such multilateral groupings healthy is far from easy. But as things stand, Nato offers the only real command-and-control arrangements to deal with a Russian land grab in Eastern Europe, most likely aimed at the Baltic states — which also are currently home to Nato-run battle groups bringing together troops from a variety of alliance nations.

That would be particularly important given the hybrid and unpredictable nature of modern warfare, particularly where Russia is involved. Earlier in November, the US Army Training and Doctrine Command MadSci Network published a scenario in which Moscow whipped up discontent among Russian-speaking residents of the Baltic states, using deepfake videos to fracture the alliance and seize terrain while barely firing a shot. Whether Nato's existing structures would be sufficient to deter or prevent this remains unclear — but what Macron appears to be arguing is that the alliance is already so damaged that alternative arrangements are already necessary.

Whether such a provocative approach is the best beginning for December's Nato summit is an open question. What it should do, however, is force other European countries to really consider how to make the alliance work — including in a world where the US might no longer be committed to it.

• Apps is the founder and executive director of the Project for Study of the 21st Century (PS21)

Reuters