The government of Poland says it’s been unable to execute an arrest warrant issued by Germany for a suspect in the 2022 sabotage of the Nord Stream pipelines, which were built to carry natural gas from Russia to Europe. The pipelines were severely damaged in a series of underwater explosions in the Baltic Sea that the United States initially blamed on Russia. A 44-year-old Ukrainian diving professional identified as “Volodymyr Z.” is alleged to have attached explosive charges to the pipelines with two other Ukrainian nationals. Polish authorities say the suspect fled to Ukraine in July.