U.S. military strikes on three Iranian nuclear facilities overnight into Sunday failed to destroy the core of Iran's nuclear program and likely set it back by only a few months, according to an early Defense Intelligence Agency (DIA) assessment reported by CNN and described by three sources familiar with it.

U.S. strikes hit Iran's Natanz, Fordo, and Isfahan nuclear sites, escalating tensions in Israel-Iran conflict.

The IAEA, the UN's nuclear watchdog organization, said on Sunday that the nuclear facility attacked by the United States in Isfahan, Iran, contains little to no nuclear material.…