France refused for years to extradite, because the US has a death penalty.
The diplomatic way to handle that BS would have been to suspend all US-to-France extradition proceedings.
The best way to handle it would have been to hire a small gang of French yoots to drag the filthy animal by his hair, and beat him slowly but surely to death in the street.
http://www.freerepublic.com/tag/iraeinhorn/index
Or, send a squad of Special Ops to abduct him and bring him back for trial, like the Mossad did with Adolph Eichmann.