External Tactical Support Force (ETSF), a defensive force, is a subordinate branch of the Antares People's Liberation Army (APLA), aimed at ensuring that the Antares Alliance provides support to one or more sides of the war without directly participating in the war.
Generally speaking, ETSF is divided into three parts - air defense forces, artillery forces, and blockade forces. ETSF theoretically cannot equip tanks, aircraft, warships, and ground missiles. If equipped... that is APLA.