When Exxon Mobil Corp. Chief Executive Rex Tillerson detailed a deal to drill for oil in Russia’s Arctic Sea two years ago, he predicted that the project would strengthen the ties between the U.S. and Russia. Instead, Exxon has wound up in the cross hairs of U.S. foreign policy, which could threaten one of the company’s best chances to find and tap significant—and much needed—amounts of crude oil. The U.S. on Thursday announced new sanctions targeting Russia’s financial, defense and energy sectors in a bid to punish the Kremlin for stoking the military conflict in Ukraine. Details of the sanctions, designed to match new measures imposed by the European Union , are set to be released Friday. A U.S. official said the new penalties would affect Exxon’s current drilling in the icy Kara Sea with its Kremlin-controlled partner, OAO Rosneft , though the extent of the impact was unclear […]