The U.K.’s former ambassador to the U.S. has a theory on why President Donald Trump left Iran’s nuclear deal. Kim Darroch said Trump abandoned the international deal to spite his predecessor Barack Obama. According to Business Insider, Darroch said Trump’s move was “diplomatic vandalism.” In a 2018 memo, he said the U.S. didn’t have “any ‘day-after’ strategy” for their departure from the deal. Darroch recently resigned, saying it became “impossible” for him to continue his job.