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.

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

Iran doesn’t have nuclear weapons. But it has enriched nuclear fuel to levels that put it within weeks of having enough fissile material for a bomb. Still, Iran hasn’t proved it can build a reliable nuclear device or miniaturize one to fit atop a ballistic missile.