Wouldn't it be possible to make a UN treaty that no country is allowed to sell arms to foreign nationals, with economy-busting fines to be paid into the UN's central fund by any country discovered doing so?

And that no country can produce more arms than it logically needs for self-defence against a credible threat.

And that no country could use arms to suppress dissent.

If countries couldn't buy arms, and could only use what they produced themselves, surely all these wars would stop?

As for the various dictators, aren't they all out for the money? Couldn't they just be put on islands full of luxuries and given lots of money to spend where they couldn't harm others?