"The problem is that nuclear weapons are too attractive to powers with weaker conventional militaries."

They are attractive to everyone. Note that the 2 biggest nuclear powers also have the most powerful conventional militaries.

Nuclear weapons arguably did end full scale war as we know it and the 'cold war' is not over, it's just thawed.

WW2 ended due to them basically - and Korea was stalemated when Eisenhower demonstrated artillery based nukes as a 'signal' to the Chinese.

Korea was the last 'real war' - since then it's been smaller scale stuff, insurgencies, smaller nations fighting, NATO overruns (Iraq, Libya, etc.).

It will take another 50-100 years to denuclearize.

The only way to stand-down is to create a framework wherein there is reasonable assurance of balance of power.

You can see North Korea's push to nuclearize is actually fairly rational survival strategy. Once they are fully there, they are too dangerous to fight. I'm not saying I agree, I'm saying it's a reasonably rational move for a self-interested entity.

As for 'ban' - who 'bans'? There is not international power than can ban this stuff. The UN? Where is the UN's army to enforce the ban? See what I mean? ...