>... with a court punishing international crimes.
that's the whole thing, the US doesn't agree with that assessment.
US does agree with that assessment. US however think that international crimes are cool. Especially if they do it, but not only then.
Which is fine, inside the US. But when Americans leave the US, they are no longer under US law, theyre under the law of whatever country they enter. Which means, if the country acknowledges the ICC, any American in that country falls under it. Just like a tourist in America has to follow American laws.