It's actually a good ideea,altough an impractical one.Imagine no nukes.....tea in Moscow by now.
This is just a PR stunt by Iran. The reason(s) for any country to justify, mostly to itself more than to other countries, as to why it needs nuclear weapons are many, so let us leave them out for now.
Science fiction movies toss around the idea of 'world ending' events, etc. A nuclear war is essentially a 'nation ending' event, especially for smaller countries. The capability to make a nuclear weapon is an insufficient threat, more like a non-threat, and everyone knows that. That mean the capability to make a nuclear weapon is a threshold we want everyone to stop at.
That threshold is both philosophical and technical.
It is philosophical in the sense that we strives to convince countries that they do not need nuclear weapons. For the most, we have succeeded.
It is technical in the sense that making even a single functional nuclear detonation device, not yet a deliverable device, have enormous technical hurdles. The technical threshold does not consider financial because financially speaking, if determined enough, many countries will allocate the necessary funds to embark on a nuclear weapons program. Pakistan's famous 'eat grass' determination is an example of this. Pakistan have many internal issues but was willing enough to sacrifice progress in those issues in order to have a nuclear weapons program independent of external influences. This is not a negative criticism to Pakistan but just an observation that we can shelve the financial threshold under the technical threshold.
The unwillingness to violate borders, or the respect for sovereignty, is the reason why we have agreements, treaties, pacts, and so on. We basically expect each other to respect the moralities and principles of an agreement and finally to obey them. We may attach some forms of punishment, such as economic punitive measures, withdrawal or denial of aid, ejection from an alliance, etc., should there be violations, but ultimately, we rely more on shared values than punishments to get members to obey.
So far, most countries in the world agreed that there is no need for them to have their own nuclear weapons program. This is not because they were threatened by US and/or Soviet/Russia. They have seen what nuclear weapons did in WW II and they do not want such a fate mete upon them. At worst, we can say that most countries are both morally abhorred and threatened. But since the end of the Cold War with the US and Russia continuing to reduce our collective nuclear weapons stockpiles, most countries leans toward moral distaste for nuclear weapons than from being threatened by US and/or Russia that they hold themselves at the 'capability' threshold. This is why we should dismiss the criticism on -- why the US is somehow 'allowed' to have nuclear weapons and no one else does -- as intellectually juvenile.
This is why this is nothing more than a PR stunt by Iran. Iran is perfectly free to rid herself of her nuclear weapons program with nothing more than an internally generated moral distaste for such weapons. This is not about Israel, although many would and have made it so. The reality is that Israel is nothing more than a convenient 'look at this shiny object' that every Muslim use to distract from the real issue: That there is no need for nuclear weapons.