What Iran is asked to do in terms of meeting its requirements under the IAEA is no more or less than any other country that is signed up, and simply put its not meeting the same standards as other countries.
Letting inspectors in the country is pointless if you then refuse to allow them access and provide information that they have requested, which is exactly what Iran does.....
http://www.iaea.org/Publications/Documents/Board/2013/gov2013-6.pdf
...also as a signatory it is bound by that agreement to provide the IAEA with access and information (as is every country that sings - the difference is that they do and Iran doesn't). Nothing 'backwards exists at all - only Iran's refusal to provide access and information.
I also notice you didn't both with answering any of this:
So out of interest what would you do with the likes of Iran and NK? Do you believe they would be OK with a nuclear weapon that could be delivered? If not then exactly what would you suggest, given that asking them nicely has had utterly no effect at all?