The United Arab Emirates’ decision to leave a global cartel of major oil-exporting countries is seen to reflect a widening fracture within the Gulf Cooperation Council (GCC).The UAE announced on Tuesday that it would leave the Organisation of the Petroleum Exporting Countries (Opec) and the wider Opec+ alliance, effective on Friday.The country joined the group in 1971, though one of its emirates – Abu Dhabi – joined in 1967.The UAE’s Ministry of Infrastructure said in a statement that the...