Ships can register any nation as their flag state, so they often choose flags of convenience based on whoever has the lowest fees or regulations -- or more insidiously, whoever has the least ability to hold companies accountable.

This is why so many shipping companies register in Liberia, Panama, and the Marshall Islands. Also Mongolia, which is landlocked.

So unless we want to fill the oceans and ports with ships that have nuclear reactors with no regulation, no safety measures, and no accountability, we're gonna have to fix the last hundred years of international maritime law.