The Demilitarized Zone is located in the south-eastern portion of the Southern Province. It is the first area the player will visit in the game, with the headquarters for the AN forces based around the Joint Security Area found in the real-life Korean DMZ.
Initially when the mercenary arrives at the DMZ, the North Koreans have established a stranglehold on the Allied base; numerous KPA soldiers are attacking the Zone in unprecedented numbers, and to make matters worse, Jin-ho Yong, the Two of Clubs, is bombarding the area with artillery. Over the course of the campaign, the hill from which Yong directed the artillery barrage becomes an AN landing zone complete with helipads and fuel storage.
During the first AN contract (also the first contract in the entire game), the mercenary is instructed by Colonel Garrett to verify the Two of Clubs, along with silencing his artillery. Yong is fairly easy to find, and he is only minimally protected. After you've either killed or captured him, the Allies will allow you access to three free uses of their Surgical air strike to eliminate his artillery, which is located on the cliff facing towards the DMZ.