The United States sharply tightened energy sanctions against Iran on Thursday, seeking to cut the Islamic Republic’s exports to zero and ushering in a new era of uncertainty for the oil market. President Donald Trump restored Obama-era sanctions against Iran last year but granted waivers to eight nations, allowing them to import limited quantities of Iranian crude. Last week, his administration surprised the market by announcing it would not extend the waivers . Investors and analysts expected Trump to tighten the waivers every six months, allowing China, India, Turkey and other importers to gradually wind down purchases of Iranian crude. The […]