Military contractors linked to the Kremlin have seized control of two of Libya’s largest oil facilities in recent weeks, heightening tensions between Russia and the U.S. over Moscow’s growing footprint in the turbulent North African nation. Since June, armed fighters from the Wagner Group, a Russian firm with ties to the Russian government, have moved in to secure Libya’s largest oil field and its most important oil-exporting port, Es Sider. The advance has helped Libyan warlord Khalifa Haftar maintain a blockade of the country’s…