Mutual disarmament does not work, if you think it would then you might be best served studying human history in warfare and human nature in general.
The proverbial cat is out of the bag. the milk is spilled and you can't unspill it.
disarmament is one of the few ways you can guarantee a nuclear war.
in fact things would go the other way, with cheaper and smaller nuclear technology, newer, more precise and more efficient nuclear weapons are inevitable. Diplomatic deterrence, MAD doctrine and effective countermeasures against delivery systems are practical means of actually reducing the risk of nuclear war.
let's say everyone in the world disarmed. it takes one unstable country or blood thirsty leader in one country to secretly build a nuke and use that dominate other countries. Is it unreasonable to anticipate that, given our species' history? When that happens, not only would it restart an arms race, other countries would be forced to use their newly developed nuke either in retaliation or preemptively. You also have to keep in mind the human prejudice, "a thief always suspects others are trying to steal from him." official stockpiles may be discarded with but secret and unofficial nukes will always be there because militaries and will always suspect other militaries to be as devious as they themselves are.
Lastly, look at the START treaty, after Putin got all war hungry, he suspended Russia's participation, because he realized even a smaller country like Ukraine can challenge Russia's ability to dominate geopolitics or even remain sovereign without nukes. North Korea rightfully anticipated that nukes were the only way they could preserve their government (for better or worse). The problem of war itself would need to be solved before nuclear disarmament can be a practical solution.
The proverbial cat is out of the bag. the milk is spilled and you can't unspill it.
disarmament is one of the few ways you can guarantee a nuclear war.
in fact things would go the other way, with cheaper and smaller nuclear technology, newer, more precise and more efficient nuclear weapons are inevitable. Diplomatic deterrence, MAD doctrine and effective countermeasures against delivery systems are practical means of actually reducing the risk of nuclear war.