Re: It's not clear that Iran has that right.
Though there is some problems in the language of the NPT, the clear reading of the text is they only have rights under Article IV if they comply with the rest of the treaty - including Article III.
No country has actually followed the treaty perfectly. I'm not a legal expert, but from everything I have read, nobody close to the situation feels that they can point to a violation of any significance. The IAEA says that they have no evidence that Iran is trying to build a bomb. Even the US says that they expect Iran to need another decade before they can build a bomb.
As much as Iran refining nuclear material makes us nervious, we can't invade simply only a strong theory that Iran is building a bomb. Heck, the US government claimed much stronger evidence before the invasion of Iraq and look how many WMDs they turned up.
I heard someone on a news show (maybe on the BBC) say that it only makes sense for a country to have its own uranium reprocessing facilities if it has more than 40 reactors. The facilities are expensive to run, and it makes much more sense to buy/lease uranium for power reactors from other countries.
Only if you trust those countries. If your depending on another country for nuclear fuel, they have a big stick to hold over your head.
Jay