“The Russians using cluster munitions is obviously a war crime!!!”
Neither Russia or Ukraine are parties to the Convention on Cluster Munitions so any claim of a ‘war crime’ by either is not going to be held up by the facts.
https://treaties.un.org/Pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XXVI-6&chapter=26&clang=_en
Russia nor US are parties to the ICC.