TLDR: he's a member of the ICC. Issues warrants against Israeli political leaders. Neither Israel nor the USA (nor China, Russia, India) are parties to the international conventions that formed the ICC. He's being sanctioned as a result by the USA, which flowed down to US companies who must follow US law.
If the sanctioned Israeli politicians and military commanders think those warrants are baseless, why don't they appear before the courts to defend themselves? This isn't really about the ICC judges. It is about the failure of the major Western countries who are part of the ICC to come to the defence of the judges who they have appointed to make those decisions, and the control Israeli politicians exercise over the Wh…
I mean, it’s causing a small rift in the GOP. Time will tell if that escalates any though. I stand firm in my believe that nothing ever happens though.