human
Why did the US agree to lift sanctions on Iran?
assistant
The US agreed to lift sanctions on Iran because Iran agreed to curb its nuclear program. The US wanted Iran to stop enriching uranium, which is a process that can be used to make nuclear weapons. The US wanted Iran to stop enriching uranium to 20%, which is the level at which it can be used to make nuclear weapons. Iran agreed to stop enriching uranium to 20% and to not pursue nuclear weapons.