: Reporting from Behind Enemy Lines explores how independent journalists report from conflict zones at great personal risk. Historical Documentation and Essays
In a more literal sense, if you were referring to a common phrase in the fountain pen hobby, enthusiasts often discuss Behind Enemy Lines - Bad Paper! —which focuses on how certain inks perform on low-quality, "common" paper like standard copy or notebook paper.
: The article Brothers across Enemy Lines documents the letters between a mission president and a German soldier during World War I.