Resistance to the idea is grounded in fears of what actions might be justified in the name of a U.N. designated mass atrocity. China and Russia have still not fully recovered from the Libyan affair in 2011, when they refrained from vetoing a Western-backed U.N. resolution approving military action to protect civilians and calling for a negotiated political solution to the conflict — and then watched NATO use that resolution as legal cover for a campaign to overthrow Col. Muammar Gaddafi.