A blossoming Sino-Russian romance is undercutting U.S. global interests on an unprecedented scale. Indeed, Russia and China seem to have their eyes on restraining European and Japanese power, too.Start with the United Nations, where Russia and China are hampering U.S.- and European Union-led efforts to address Iran's nuclear program. It's been weeks since the Security Council got official notice that Iran had violated its nonproliferation promises - yet the U.N. body has yet to manage to even condemn Tehran's actions, much less impose economic sanctions.No surprise: Both Moscow and Beijing have way too much at stake to bully their buddy,...