China

I expect what he’s responding to are recent tests of nuclear-powered and nuclear-capable missiles by the Russians…but those tests did not include the testing of nuclear weapons, so it’s a bit unclear what he’s actually talking about."

Dan Marks, the Rusi report’s author, said ministers should be wary of the influence this would give Beijing over Britain, not only through supply chains but also vulnerabilities through potential software updates that were regularly required to maintain equipment. He stressed the risk of China directly threatening the UK’s kit, or of using access to IT systems to sabotage equipment, was low because it would damage the reputation of Chinese firms globally. But he added: “As we saw with Russia threatening to cut off gas supplies to Europe, if the stakes are high enough than these kinds of considerations go out the window.”

Darya Dolzikova, Senior Research Fellow for Proliferation and Nuclear Policy at the Royal United Services Institute (Rusi) - a London-based defence and security think tank - said she did not believe Trump's comments would change the situation massively. But, she added, "there are other dynamics globally that have raised the risks of nuclear exchange and further proliferation of nuclear weapons to levels higher than they have been in decades". Trump's message, she said, "is a drop in a much larger bucket, and there are some legitimate concerns of that bucket overfilling".