An unprecedented new international moral and legal rule forbids one state from hosting money stolen by the leaders of another state. The aim is to counter grand corruption or kleptocracy (-rule by thieves-), when leaders of poorer countries--such as Marcos in the Philippines, Mobutu in the Congo, and more recently those overthrown in revolutions in the Arab world and Ukraine--loot billions of dollars at the expense of their own citizens. This money tends to end up hosted in rich countries. These host states now have a duty to block, trace, freeze, and seize these illicit funds and...