JULIAN BORGER North Korea’s and Iran’s ambitions to become nuclear powers may make US plans to cut its own warheads difficult to pass. President Barack Obama is expected to address the threat posed by North Korea in tonight’s state of the union speech, after news of Pyongyang’s third underground nuclear test triggered some last-minute rewriting of the presidential text. North Korea’s show of defiance, possibly timed to overshadow Mr Obama’s speech, has come at a moment when many of the president’s leading advisers on Asia have left the administration and have yet to be replaced. But it will require a statement of presidential intent to calm a nervous...
