The appraisal that Iran’s nuclear hopes had been set back 1 to 2 years by U.S. and Israeli bombings was the latest in a shifting series of pronouncements.

The new assessment contrasted with U.N. agency view that Iran could resume enriching uranium in a “matter of months.”

Several experts have cautioned that Iran likely moved a stockpile of near weapons-grade highly enriched uranium out of the deeply buried Fordow site before the strikes and could be hiding it.