lines of communication
Military and logistics term for supply and communication routes between a rear base and front-line forces.
Cutting the enemy's lines of communication was the key to the operation.
兵站線 is a more general term for supply lines, while 後方連絡線 specifically emphasizes communication and supply routes from the rear.
Compound of 後方 (rear, behind) + 連絡 (contact, communication) + 線 (line, route). The exact historical derivation is uncertain; the term is conventionally used in military contexts.