As the U.S., Israel and others try to assess the extent of damage done by the U.S. and Israeli strikes on Iran's nuclear program, several facts need to be established, on top of whether enrichment halls at Natanz and Fordow were rendered inoperable.

Fordo is probably the most spied-on place on the planet - and work to understand what is happening there is set to intensify further.

A leaked ‘preliminary, low confidence’ report from the DIA suggests U.S. attack on Iranian nuclear sites only set program back by months.