The map created using a simulation tool shows the devastating impact of a hypothetical U.S. nuclear strike on Tehran, Isfahan, and Qom.

Haifa and Tel Aviv struck by Iranian missiles as U.S. embassy in Israel directs government employees and families to shelter in place at home.

Nine countries currently either say they have nuclear weapons or are believed to possess them. The first to have nuclear arms were the five original nuclear weapons states — the United States, Russia, China, France and the United Kingdom.

If the U.S. decides to support Israel more directly in its attack on Iran, one option for Washington would be to provide the “bunker-buster” bombs believed necessary to significantly damage the Fordo nuclear fuel enrichment plant,

Israel has targeted the secretive Fordow facility in recent days but, according to the IAEA, so far it has either been unwilling – or unable – to damage it. Here’s what we know.

The strikes are part of an air campaign Israel launched against its longtime foe five days ago, targeting Iran’s military and nuclear program.

China has an estimated 600 nuclear warheads—an increase of 100 in just one year—the Stockholm International Peace Research Institute reported.