Special counsel Robert Mueller's office appears to be in an early stalemate in its efforts to bring a criminal case against Russians allegedly involved in Moscow's efforts to influence the 2016 presidential election. Although one Russian company indicted by Mueller in February, Concord Management and Consulting, has US attorneys and a court hearing scheduled, the special counsel's team hasn't been able to reach the company or its co-defendants. The Russian government's top legal office wouldn't accept paperwork from US law enforcement in the case, and the company has already hit back at Mueller by demanding more evidence and information. The...