But the point about the NPT is that it is supposedly international law. Iran is a signatory, whereas IIRC India, North Korea and the Red Sea Pedestrians are not. As a signatory, Iran has disavowed the development and/or acquisition of nuclear weapons which it has not had prior to signature.
The organisation responsible for monitoring compliance with the NPT (the IAEA) has identified that there are valid concerns that Iran is not complying with the treaty it has signed and is asking for various issues to be clarified. Iran is responding to this with various obfuscations and a nuclear facility hardening programme that does nothing but increase suspicions.
The part of the UN responsible for enforcing international law (UNSC) has responded to this with a whole range of sanctions etc, as have other "blocs" such as US, UK GE & FR, as they are entitled (should that be required?) to do under international law.
Now in response to this, Iran can do a number of things, such as open up all facilties for full inspection & monitoring or unilaterally withdraw from the NPT. They have (understandably) chosen to stay within the treaty but not accede to the inspections requests. Whether Iran is justified in wanting nukes (and I agree with Widger) is irrelevant, they have forsworn them under treaty. Not a situation I believe exists with the denizens of the new Uncle Kim's happy land, or the Red Sea Pedestrians.
I appreciate all this is nice legal theory and as such fairly naive, but the point then becomes, does the UN enforce international law or does it give it a stiff ignoring if it all gets a bit difficult, which tends to happen with the really important things?
If it doesn't, what is the UN for? Is it to disappear in a puff of logic?