The White House has threatened sanctions on any country that trades with Iran in another bid to economically isolate the country, as US military efforts falter. Launching what he called Operation Economic Outcast, the US Treasury secretary, Scott Bessent, compared it with D-day. China, Iran’s biggest trading partner, has already signalled that it will not cooperate with Trump’s attack on the Iranian economy. Lucy Hough speaks to Julian Borger, senior international correspondent