You don't need to directly control these systems to have a big influence. People in these countries (a tiny minority of humanity) opt to stay and pay the taxes

You don't need to directly control these systems to have a big influence. People in these countries (a tiny minority of humanity) opt to stay and pay the taxes that maintain these systems. But the main moral culpability is just not caring. Nuclear safety isn't even on the mind of the average voter in the US or Russia. If it were an issue as important as major wedge issues as say guns or religion are in the US even a small fraction of the population could have a major impact.