When does a nation have a license to kill? That's easy enough to answer. Any Islamic and/or Arab country, with Russian and/or Chinese support, pretty much has a free hand to perform as much 'ethnic cleansing' as they want. Or they are free to oppress any designated minorities within their borders (Jews are preferred in this role, but any non Muslims will do in a pinch). Chinese and Russian support can include any preferred business relationships, diplomatic support, or weapons deals. Having friends in Beijing and Moscow also brings along the all-important UNSC veto, which is very handy in keeping away sanctions. Just ask Sudan about that.