[bayesianhorse]

It's hard to judge what is more secure... a promise of essentially the U.S. government that the gold belongs to us (Germans), and would be available for sale, or storing the gold in Germany, where it can be seized by an invader, and maybe even ordinary criminals or corruptions. And it would have to be moved again to be sold in bulk, because once Germany needs to sell vast amounts of gold, nobody would trust Germany to just write IOUs.

Times have changed. Invasion has become unlikely, despite Germany having borders to several foreign countries, with a history of centuries of conflict in Europe. Even corruption is unlikely today to take away significant portions of such a gold depot.

Still, the only purpose of this gold is as a currency, and as such it doesn't matter that much if it is stored in Germany or in some country you would probably have to trust anyway to make use of it.