oneworld2:
No, not the same really. Only in the case of Ukraine do we have an ex-nuclear power which demonstrated responsibility with its nuclear arsenal through very turbulent times. Furthermore, Ukraine signed an agreement with Russia and other major powers to divest itself of its nuclear arsenal with the explicit assurance that Russia would respect its sovreignity and along with the USA, France, The UK and China IIRC would defend Ukraine in the event of an attack. None of the signatories have lived up to their solemn obligations under the Budapest Agreement and so the agreement is null and void, legally returning Ukraine to the nuclear club even if it possesses no known nuclear weapons at the moment.
Iran, Syria, Yemen, North Korea, never were nuclear powers and so are not in the same situation as Ukraine is. They never possessed nuclear weapons and then gave them up by treaty, which was later breached. The only other power which gave up a functional nuclear arsenal as far as I know was South Africa. Gaza is not a state and Palestine is in too bad a state to responsibly possess nuclear weapons. The status of Israel is difficult due to its policy of "strategic ambiguity" with respect to nuclear weapons and delivery systems. The situation is made worse by the political protection offered to Israel by the USA over nuclear compliance and inspection.
As an editorial note, I would say that I would feel more comfortable in a world where Iran possessed nuclear weapons instead of volatile and unstable Pakistan. The argument that if Iran got nuclear weapons, then Saudi Arabia would get them has always struck me as absurd because as a condition for funding and assisting Pakistan in its nuclear programme, Saudi Arabia got a guarantee that Pakistan would supply it with nuclear weapons if the Saudi kingdom needed them in the future. So Saudi Arabia has been weeks away from being a nuclear-armed military power since the 1960's.
Cheers.
Evilroddy.