Iran says its nuclear program is for civilian energy purposes, and so peaceful. But it had enriched uranium to a near weapons-grade level, and well beyond what is needed for energy, putting it close to developing a bomb if it opted to do so.

Iran could start enriching uranium again within "a few months", says the IAEA.

Republicans Break with Trump on Iran. Story by John Baker • 11h. 1 / 8

Iran is assessing the damage and lashing out over the American and Israeli airstrikes that damaged its nuclear sites.

Some nuclear proliferation experts told ABC News they believe the strikes could lead to a "fork-in-the-road" moment that results in Tehran taking a more dangerous and secretive path to obtaining nuclear arms if it chooses to do so.

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