Combat zone and Theater of operations

Combat zone noun - A military area where combat forces operate.

Theater of operations and combat zone are semantically related in military area of war topic. In some cases you can use "Theater of operations" instead a noun phrase "Combat zone".

Theater of operations noun - A region in which active military operations are in progress.

Combat zone and theater of operations are semantically related in location of military fights topic. You can use "Combat zone" instead a noun phrase "Theater of operations", if it concerns topics such as place of warring.