This is untrue - Israel has investigated war crimes, e.g. famously things like what happened at the Sde Teiman prison.
> So if you want accountability, drive that internally with your politicians and get Netanyahu/Likud out of office
Many have been trying for years. It's not trivial. (About half of Americans dislike {current_president}, whomever that is, but there's very little they can do about it in between elections.)