(I’m just going to be talking about nukes specifically here) I think that we should get rid of most of our nuclear weapons to prevent conflicts. However, we should keep a small international stockpile. Some kind of committee would be formed in which every country is a member (probably under the control of the UN). When a county wants to use the weapons, a majority of countries would have to agree that they could use it.
That probably was a bit unclear so I’ll give an example: Imagine a country, let’s say France, gets is fighting a war against some other country. Currently, France has nuclear weapons and they could use them if their government deemed it necessary. But with the international committee, the majority probably would not be in favor of nuclear weapons being used (because of MAD and all that). But in some major global threat (imagine an alien invasion or something), countries would probably be able to use nuclear weapons because a majority of them would be in favor of doing so.