Russian forces have conducted a series of operations against the U.S.-led coalition in Syria this month, including one this week at a strategically located base in the southern part of the country, U.S. military officials said. The Russian actions have alarmed U.S. military officials, who are concerned that a miscalculation might escalate into an unintended conflict between the U.S. and Russian forces in Syria. Tensions between the two countries are already high following Russia’s invasion of Ukraine in February and American efforts to arm the Ukraine military to defeat Russian forces there. On Wednesday, Russia carried out airstrikes at the...