The Strategic Defense Coalition (Simplified Chinese:战略防御联盟) (Traditional Chinese:戰略防禦聯盟) or SDC is a faction in Call of Duty: Black Ops II. They are an East Asian Chinese-led strategic military alliance.
Depending on how the player performs in the Strike Force missions, Russia, India, Afghanistan, and Iran may become members, or alternatively they will ally with the United States and NATO and assist in trying to stop Raul Menendez.
If the player succeeds in all of the Strike Force missions, the SDC will ally with the U.S. and defend the U.S.S. Barack Obama from the drone attack in the mission Odysseus and will also send elite troops to eliminate Mercenary snipers in the mission: Judgment Day.
They also appear as a faction in multiplayer, facing SEAL Team Six on Cargo, Carrier, Drone, and Mirage.
Judging by the holo-map in the briefing before the start of the Strike Force mission, SDC has a considerable amount of members from different countries. Admiral Briggs also directly states that, if Russia joined the SDC, they would be the single-largest military alliance on the planet.