President Trump, who has long considered Iran to be a threat to the U.S., pulled out of the 2015 nuclear accord in May 2018. The deal, which the U.S. and five other nations struck with Iran, was intended to prevent Iran from developing nuclear weapons, but Trump thought the deal wasn’t tough enough. Instead, the U.S. has reimposed harsh economic sanctions on Iran, which has put additional pressure on Iran’s struggling economy. Critics fear the moves may also make extremists in Iran more powerful.