Pentagon leaders laid out new details Thursday about military tactics and explosives to bolster their argument that U.S. attacks had destroyed key Iranian nuclear facilities, but little more emerged on how far back the bombing had set Tehran's atomic program.

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,…

Classified findings indicate that the attack sealed off the entrances to two facilities but did not collapse their underground buildings.