All countries are above the law. When was the last time you saw a country in jail or meaningfully punished? The only one who can punish a country is another country if they are powerful and violent enough.
It's one thing to say: "We will not recognize or abide by ICC verdicts".
It's another thing to say: "We will dismantle it if it goes after Americans".
It's also extremely hypocritical since Rubio himself co-sponsored a resolution backing the court's jurisdiction over Russians accused of war crimes.
So it's really more like: "If it says things we agree with, we will be on board. If it says things we disagree with, not only will we not be on board, we will erase the whole thing".
Which is why the ICC was established by several countries as part of an international agreement. It's literally other countries collaborating to punish bad actor countries.
A country is an abstract idea at the end of the day. How can you put Uganda in a physical jail? Or how can one country "punish" another?
If you're talking about invading and occupying the people, every person is still theoretically under the law of whatever country they are in by default.
Who should be responsible for enforcing the Geneva Conventions and other international humanitarian law? Or are we finally admitting that the only "international law" we officially recognize is Might Makes Right?