foxhole circuit
originally US
noun
(Originally, with reference to theatrical shows staged for American troops by the United Service Organization during the Second World War (1939–45)) the circuit of shows going as close as possible to the front lines, as opposed to performances at military bases or hospitals; (later more generally) theatrical shows staged to entertain troops in a war zone.
Origin
1940s; earliest use found in Wichita Daily Times (Wichita Falls, Texas).