But you can’t force them to accept a foreign sovereignty. It would be like the USA saying that US federal law now applies to Greenland, and they have a right to participate in federal elections.
> I'm not convinced that the absence of an ICC-like institution would in any way help disenfranchised people with gaining these rights.
I’m not convinced that the ICC is capable of helping anyone. They can run tribunals after-the-fact, if some other power has already taken care of the perpetrator, which may be useful in some situations, like when a devastated country doesn’t have the resources to run a trial themselves, but it can’t prevent or stop anything from happening. Doing that would usually mean the ICC would have to raise an army and go to war.
For example, in 2024 the ICC issued arrest warrants for the leaders of Hamas. Palestine, which is a signatory, did nothing to try and arrest them. Neither did any of the other ICC countries, because executing that warrant would require going to war in Gaza (which is what Israel did). Neither has the warrant for Netanyahu made any difference.