Er no, any country is allowed to enrich Uranium under the NPT, provided it is for non weaponry purposes. Iran is the only country that is exempt from this, it has it's own NPT, and this is not because it is enriching, it's more to do with political maneuvering.
Now I say Iran should be open about it's enrichment thus ending the need for it to be sanctioned. But to be frank with the politics that is around now, only non-enrichment would ensure this, despite this not being a part of the NPT treaty, albeit a sticking point. Obviously at one point, when German et al engineers and technicians gave them the technology to enrich Uranium, it was ok for them to do so, now for some reason I'm not quite sure about, it isn't. If they were working towards nukes, it seems that the US has gone an arse about face way of achieving sanctions, albeit deserved but for the wrong reasons.
It is fairly sanctioned but not for breaches of the NPT as regards enrichment, it is sanctioned because of it's desire to do so in a less than open manner. That is its only breach of said treaty, if you don't believe me I suggest you read the terms of the treaty to which Iran was a signatory.
It's a little bit more than just it's lack of opacity. But the effect is much the same.