While I'm not sure of all the legalities, it would appear that the Vatican is the closest one can get to a "successor in interest" to the Roman Empire. And claims have been made over the centuries that the Vatican sits on the Temple treasure. Whether those claims are true are for a court — armed with sub-poena power and the right to force the Vatican to open its doors, at gunpoint if necessary — to decide.
Otherwise, we do not know.
But even if it isn't true, the Bishop of Rome will at least be met as a criminal, which is what faces Israeli leaders in Europe for truly fictional crimes. Their only crime, where they may have actually done it, was to defend the Jewish nation against genocidal Arab savages bent on massacring it. It's important that Europeans get a taste of what they are dishing out, and Karl Ratzinger is a European. The Europeans have hated us for centuries because of their "religion of love," Christianity. They have actualized that hatred into rapes, massacres, murders, discrimination, and finally a holocaust of a third of our people. In the last two decades, these scum have done all they can to de-legitimize our country, and to ban our religious customs from being practiced in their own countries. Turning Europe into a Jewish graveyard was not enough for them, apparently.
So, let the warrants be served - and let the European scum understand how lowly we truly hold them. Now, let the bastards have a real reason to hate us.