Iran has not produced the highly enriched uranium necessary for a nuclear weapon and has not decided to do so, U.S. intelligence officials told Congress yesterday, an assessment that contrasts with a stark Israeli warning days earlier that Iran has crossed the “technological threshold” in its pursuit of the bomb. Director of National Intelligence Dennis C. Blair said that Iran has not decided to pursue the production of weapons-grade uranium and the parallel ability to load it onto a ballistic missile. “The overall situation — and the intelligence community agrees on this — [is] that Iran has not decided to press forward . . . to have a nuclear weapon on top of a ballistic missile,” Blair told the Senate Armed Services Committee. “Our current estimate is that the minimum time at which Iran could technically produce the amount of highly enriched uranium for a single weapon is 2010 to 2015.”