The News United Nations nuclear inspectors declared for the first time that they had extensive evidence of “past or current undisclosed activities” by Iran’s military to develop a nuclear warhead.

Behind the News The news seemed certain to worsen Iran’s conflict with the West. The blunt report contradicted a 2007 assessment by American intelligence that Iran had halted direct weapon-development work. Iran denies trying to build a nuclear weapon. Vice President Joseph Biden said the administration would ask the Senate to ratify the nuclear test ban treaty approved by the United Nations in the 1990s.