Nearly a year after Russia began its military campaign in Ukraine, the U.S. and its European allies find themselves in a familiar predicament: struggling to devise a strategy to get Moscow to back off. While Western economic sanctions, combined with a steep drop in the price of oil, have inflicted heavy damage on the Russian economy, they’ve done nothing to temper the Kremlin’s support for eastern Ukraine’s separatist insurgency, U.S. officials acknowledge. “It’s fair to say that costs haven’t risen high enough for the Russian leadership to rethink their course of action,” a senior Obama administration official said. As Secretary of State John Kerry travels to Ukraine to meet with President Petro Poroshenko and other Ukrainian leaders this week, policy makers in Washington are re-examining their decision not to supply weapons to Ukraine […]