World Powers Reached A Deal With Iran Over Nuclear Weapon.

World powers have reached a deal with Iran on limiting Iranian

nuclear activity in return for the lifting of international economic sanctions.
US President Barack Obama said that with the deal, "every pathway to a nuclear weapon is cut off" for Iran.
And President Hassan Rouhani said the "historic" deal opened a "new chapter" in Iran's relations with the world.

Negotiations between Iran and six world powers - the US, UK, France, China, Russia and Germany - began in 2006.
The so-called P5+1 want Iran to scale back its sensitive nuclear activities to ensure that it cannot build a nuclear weapon.
Iran, which wants crippling international sanctions lifted, has always insisted that its nuclear work is peaceful. 
Source: BBC