The “kill switch” is dominating behind-the-scenes discussions in Europe, as the continent’s leaders line up hundreds of billions of euros to splurge on their collective defence in the years ahead.
The US’s decision to stop real-time intelligence-sharing with Ukraine this month amounted to an abrupt pulling back of the curtain. We don’t often see any of the workings of intelligence co-operation, much less its direct impact on the battlefield. But what Washington’s announcement – which has now been reversed – laid bare for other European nations was undoubtedly significant.
With great uncertainty caused by policy shifts in the White House since Donald Trump’s inauguration in January, Europe has finally absorbed the wake-up call that it’s only been talking about for a decade and a half. The resources that the continent’s leaders plan to allocate to its defence will be substantial, and many hope that these will be transformative to Europe as a military power.
However, there is an immediate crunch for the continent as it looks to spend some of this money on supporting Ukraine. Given the uncertain nature of its ties with the US, is there a guarantee that it won’t be put on a short leash by Washington when it buys American systems? French President Emmanuel Macron feels very strongly about this. In the manner of the post-Second World War general-turned-president Charles de Gaulle, Mr Macron is seized by the importance of Paris as a player in defence and strategic affairs.
At the weekend, he used newspaper interviews to stress to his fellow European leaders that he would be campaigning for a “Europe first” procurement stance. “My intention is to go and convince European states that have become accustomed to buying American,” he warned, adding that each state should, instead, contemplate ordering European-made equipment. “Those who buy the F-35 should be offered the [French-made] Rafale.”
The F35 is a generation-leading fighter and bomber platform for warfare. When Germany responded to the full-scale invasion of Ukraine in 2022, by announcing a “Zeitenwende” revamp to bring its military back up to scratch, it allocated about 10 per cent of its outlay to US F-35 purchases. Berlin ordered 35 F-35s – since increased by 10 more jets – as well as weaponry for €10 billion (almost $11 billion).
But, again, can Europe trust the US? Go on Reddit and there is a social media frenzy around the eight million lines of code that built the software running the F-35. Speculation that American designers can disable the platform through this code rages back and forth.
Given that Mr Trump has called for Greenland to join the US, there is an obvious case to consider wherein this might happen. Denmark has stepped up to the plate in granting all its F16 fighters to Ukraine for its war against Russia. It has also embraced the F-35 programme. But with Copenhagen being the sovereign power in Greenland, the risk of its dispute with Washington spilling over into its air force capabilities cannot be eliminated. (For what it’s worth, Ottawa finds itself in a similar situation as Mr Trump continues to call for Canada to become America’s 51st state.)
Thinking through what Europe’s rising defence spending should look like is complicated by the US’s dominance in the technology domain, especially as the future of the battlefield will involve autonomous weapons, nano sensors and acoustics.
The events of the past few weeks have also highlighted Europe’s failure to provide adequate basic artillery shells needed on Ukraine’s frontlines. It is instructive that Czech President Petr Pavel had to organise a global buying spree to find the shells that Europe’s factories cannot produce. And if it is hard for the continent to produce the guns, ships and planes that are the well-established weaponry of war, then there are even tougher future questions needed to be asked.

When the finances have been assembled to buy the defence equipment, what should Europe spend it on? Where will it find its champions of tech to provide particular generations of attacking drones that can evade the enemy’s sensors as well as provide the great many of them needed to outgun the other side? Where will the capital come from to create and expand the companies that are delivering the defences of the new era? How can Europe innovate in real time?
Answering these questions won’t be easy.
There has been a stock market frenzy for Europe’s defence champions. One such beneficiary of the new investor interest was the British firm QinetiQ (pronounced kinetic). Unfortunately for the company, it lost one fifth of its value on Monday morning when its directors were forced to warn that it would not meet the profit expectations of the new investors. The trouble was that it had cost pressures for its raw materials – partly as a result of yet another White House policy shift regarding new tariffs – and it also needed to make provision for a restructuring process.
Getting these defence companies in shape to meet Europe’s challenges will not be easy. US hedge funds have bought up much of the UK defence sector over the past decade, and there are fears that some of it may have been hollowed out in the process. Meanwhile, still-independent firms such as QinetiQ need to convince investors that they can deliver on the promise of an increasing order flow.
It is for all these reasons that Mr Macron is on to something with his warnings on where exactly the new orders are being built up.