Update on Iran's Nuclear Plants

A nuclear power plant in Iran

Obama will soon most likely be extending sanctions on Iran. This will mostly target oil companies that export to Iran.

The US Senate has backed legislation allowing President Barack Obama to extend sanctions against Iran.

It would seem Obama is becoming frustrated with Iran's unwillingness to cooperate concerning their nuclear weapon plants.

The US and its allies fear Iran is attempting to develop nuclear weapons. Iran insists its nuclear programme is entirely peaceful.

To be honest, I have a hard time believing this considering that Iran hid the power plants from everyone. Why do this if your intentions are not to harm anyone?
I'm not sure I agree with the sanctions however, I'm not sure how much would be solved. Also, I feel that this goes against what Obama said in the national address. He was talking about increasing exports, but this is going in the opposite direction.

There have been three rounds of UN sanctions against Iran and the US and its allies on the Security Council have been pushing for a fourth.

Considering the neutral effect of these sanctions, I'm not sure they're really worth the effort, when other legislation should be getting considered instead.