The only 'leaders' that end up in the Hague and convicted are those forcibly captured via military action. And those 'orders' declared by the UN can, and be vetoed by China, Russia, USA, UK, and France. Guess which two use their veto all the time?

And there are not that many indications that we are moving towards that direction or we can even ever have. I guess that sort of idealism might have existed in the late 40s immediately after the UN was established but it never had a chance.

External or internal (which seems rarely feasible unless the government is highly incompetent) regime change realistically is the only thing that worked.