>My counterpoint is wondering how many would have been destroyed by ISIS or civil unrest in some of the less stable regions of the world.

This line of thought is fascinating to me.

We should preserve them for all of humanity? Who chooses the custodian?

We want a more nationalist case for repatriation to country of origin? If they get destroyed, it’s not the self-professed custodian nation’s problem or loss.

Cynical, perhaps, but you need to balance self-determination with preservation. Maybe having their artifacts back will provide a drive to stability for the sake of heritage.