A pressure drop has been detected in the Nord Stream 1 undersea gas pipeline in the Russia-Germany energy route, the operator said Monday evening, after a similar situation with its sister pipeline led to the discovery of a leak. Both of Nord Stream 1’s two lines are affected, a spokesman for operator Nord Stream AG told dpa. The pipeline’s capacity dropped to zero in an unplanned development. The cause was being investigated. Germany’s Federal Ministry for Economic Affairs and Climate Action (BMWK) and its energy monitor the Federal Network Agency said they were in contact with each other and…