What is the origin of the idiom "running battle" and when to use it?

The idiom "running battle" originated from military terminology and tactics, specifically the concept of a continuous, ongoing conflict or engagement between opposing forces. Figuratively, it refers to a prolonged and ongoing struggle or dispute in which one is constantly engaged with an adversary, often characterized by frequent confrontations or challenges. The phrase conveys the idea of a persistent and dynamic conflict that requires continuous effort and resilience to navigate.