Some experts said they believe the U.S. strikes have the potential to lead to a "fork-in-the-road" moment that could result in Tehran taking an even more dangerous path.

Iran just ended its cooperation with international inspectors, suggesting no post-bombing deal is imminent. That may point to a long game of hide-and-seek, punctuated by military action.

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