They have no jurisdiction. Either way, arresting him is the right thing to do. So of course we will not do it unless there are no other options left and we look evil on the world stage. Well the look descriptor is probably not necessary.
What we need is Biden to mandate a reassessment by the State Department now that we know there was suppressed intel in the initial report. If they report evidence of war crimes, Biden can immediately amend support of existing agreements against the advisement of Congress without congressional challenge of impeachment.