I thought the ultimate root of this situation is still 3rd Reich and the realization that, for the most part, the Nazis didn’t break any laws. They passed laws, legally, making all their horrid designs legal, then carried them out.

Which is a long way of saying, there’s a consensus that there are standards higher than national law we may want to uphold.

I know ICC is later, and also US never joined, in a somewhat hypocritical compromise. But at least the purpose and motivation, IMO, are clean and noble.