20 questions about the Iran nuclear deal: What it says, what’s at stake, what’s next

Story highlights

U.S. pulled support of Iran's nuclear program during Islamic Revolution

Since the revolution, the West has worried Iran may produce atomic weapons

France, U.S., UK, Russia, China, Germany -- and Iran -- have been negotiating deal

The deal slows Iran's program in exchange for lighter sanctions

CNN  — 

When it comes to Iran and the West, the relationship has been convoluted for decades. And this deal is no different. After days of negotiations, six world powers and Tehran reached an agreement that calls on Iran to limit its nuclear activities in return for lighter sanctions. It’s complicated politics coupled with complicated science.

Here’s a quick primer to get you up to speed.

How did Iran’s nuclear program start?

The United States launched a nuclear program with Iran in 1957. Back then, the Shah ruled Iran and the two countries were still friends. With backing from the United States, Iran started developing its nuclear power program in the 1970s. But the U.S. pulled its support when the Shah was overthrown during the Islamic Revolution in 1979.

Who are these ‘six world powers’?

The talks involved the P5+1 group comprising diplomats from the five permanent members of the U.N. Security Council: U.S., UK, France, Russia and China, plus Germany – and of course Iran. The group has been meeting in Geneva for days in hopes of reaching a diplomatic solution.

Read the deal (.PDF)

Is Iran the only nation with a nuclear program?