Now go back and read what I was replying to. It wasn’t about the ICC’s jurisdiction...the person claimed there is no such thing as international law.
In principal, Jim Noble’s point is correct: “international law” doesn’t exist independently of other nations. As you yourself stated, it only has force if enough of the big nations agree to it.
After all, which if the big nations actually accept the jurisdiction of the UN in totality? Whenever votes go against them in the Assembly, they tend to simply ignore its dictates.
International law is simply that which is enforced by the global hegemon (or, failing that, sufficiently many Great Powers).
You're just chasing your tail. Who has the authority or even the stones to enforce 'International Law'??? International Law is written on toilet paper and a good portion of this world wipe their butts with it on a daily basis. International Law is nonsense.