To demand that it is as a prerequisite for reparations is quite weird.
I'm not confident that it could be gotten to within several orders of magnitude...

China and Japan would need to pay as well, btw.

It's not a good idea to siphon billions - who knows, maybe trillions - from the richest and give to the poorest, especially when the ultimate cost might leave the former indebted for centuries at least.

At the minimum, any countries awarded reparations should have a share of the settlement awarded directly to each adult citizen, and nothing at all to the national government itself.

Anyway, let's invoke statute of limitations.