Donald Trump’s sudden suspension of military aid and intelligence support to Ukraine has reignited fears the US could have a “kill switch” installed on some of its fighter jet exports, aircraft that are vital to European security.
The claim relates to the US F-35 fighter jets, purchased by 13 European countries, including the UK.
Though there is no evidence to suggest such a ‘switch’ exists, Joachim Schranzhofer, head of communications at the German arms company Hensoldt, told Bild last week that it is “more than just a rumour”. He did not expand on what he meant by this, though he added that it would be much easier for the US to ground aircraft by blocking access to key software, which remains under American control.
Ukraine seems to be an early example of this issue. The American suspension of military aid to Ukraine does not mean Washington can switch off the F-16 fighter jets it has already sent to Kyiv; it can, however, decline to update the AN/ALQ-131 electronic jamming equipment used by the aircraft to repel Russian air defences. This would significantly reduce the strength of the F-16s.
Such a move would break European trust in American weapons manufacturers, ultimately proving problematic in the long term. Nonetheless, European countries are now asking whether the same could happen to the fighter jets they have purchased.
“If we have to fear that the USA could do with future German F-35s what they are currently doing with Ukraine, we could consider terminating the contract,” influential ex-diplomat and President of the Munich Security Conference Foundation Wolfgang Ischinger told Bild.
Last week, Gen Frederik Vansina, Belgium’s chief of defence, said that the F-35 “is not a remote-controlled aircraft”, while Switzerland’s defence ministry recently stressed its F-35s could be used autonomously.
But the ministry also admitted no advanced Western fighter jets were fully independent of US secure data communication systems and GPS satellite navigation.
Overall arms imports by European members of NATO more than doubled in the five years ended in 2024, compared with the five years ended in 2019, according to think tank Stockholm International Peace Research Institute. Almost two-thirds of those imports came from the US, an increase of around 10 per cent in the previous five years.
The US has not commented on whether they have the power to ‘kill’ a country’s use of weapons it has sold or leased.
There is, however, precedent for countries suspending weapons purchases from the US due to such issues.
In 2021, the United Arab Emirates indefinitely suspended the purchase of 50 F-35s, part of a $23 billion (£17.8bn) deal that also included drones and other advanced munitions, due to what one UAE official described as “sovereign operational restrictions”. They also cited technical requirements and a negative cost-benefit analysis as reasons for the suspension.
As Germany prepares to receive 35 F-35s in 2026, which cost them €8.3 billion, plus several billion more for the associated infrastructure, local MPs are questioning whether they, like the UAE – should never have made the purchase.
“We have to look closely and be careful,” Ingo Gädechens, former soldier and member of the government CDU party, told Bild. “If we spend so much money on a weapon system like the F-35, we must also be able to decide for ourselves how to use it.”
