WASHINGTON — In his news conference on Monday, U.S. President Donald Trump threatened to blow up every bridge and power plant in Iran, a declaration so far-reaching that some experts in military law said it could constitute a war crime. The issue could turn on whether the power plants were legitimate military targets, the attacks were proportional compared with what Iran has done and whether civilian casualties were minimized. Trump’s threat was so broad brush it did not seem to account for the harm to civilians, prompting Democrats in Congress, some United Nations officials and scholars in military law to say such strikes would violate international law. The president’s eventual actions often fall short of his all-encompassing rhetoric in the moment, but his warnings about the power plants and bridges were unambiguous both on Sunday and Monday as he set a deadline of Tuesday night for Iran to open the Strait of Hormuz. A spokesman for U.N. Secretary-General Antonio Guterres on Monday warned that attacking such infrastructure is banned under international law. “Even if specific civili
