"The US has never recognised any court that could try them ( like the ICC) and have veto powers in the UN, so they can go about committing war crimes with impunity."
They don't have to recognize the court in order to be tried in the court, in absentia if need be.
It's interesting that despite the power to try alleged US war criminals, the ICC has chosen not to.
The ICC can't choose whatever it wants, it has a charter. It doesn't invent its jurisdiction, it's built on countries participating in it. Which is why its investigating US war crimes in Afghanistan, having jurisdiction there, but not Iraq, where it doesn't.
They don't have to recognize the court in order to be tried in the court, in absentia if need be.
It's interesting that despite the power to try alleged US war criminals, the ICC has chosen not to.