Last month, Iran’s top nuclear scientist, Mohsen Fakhrizadeh, was assassinated in an ambush near the capital Tehran. The scientist, who was considered the driving force behind Iran’s nuclear weapons program for two decades, was in his vehicle with his bodyguards when the attack occurred.

Our International Editor, Lindsey Hilsum, has been reporting on Iran for over 20 years, and explains what this killing might mean for tensions in the region.

Sources: BBC, CNN, ABC, NBC, CBS