In late May, a team of Qualcomm lawyers arrived in Beijing to seal a deal with Chinese competition regulators, optimistic that they would  soon clear the last hurdle in the US semiconductor company’s proposed $44bn acquisition of the Dutch-owned NXP. 

“All the technical issues had been resolved,” said one person briefed on Qualcomm’s discussions in Beijing. “From Qualcomm’s perspective everything that needed to be done was done.”

But three days later Donald Trump dropped a bombshell. Despite earlier assertions by Treasury secretary Steven Mnuchin and Chinese vice-premier  Liu He that the world’s two largest economies would step back from the brink of a trade war, the US president announced that his administration would proceed with punitive tariffs on $50bn worth of Chinese exports.