Question: What participant in Operation Phantom Linebacker currently has about 17,000 soldiers, 10,000 of whom are stationed in South Korea? 
Related documents: [0]  [DOC] Operation Phantom Linebacker was a coalition military operation in Iraq designed to interdict anti-government fighters from entering Iraq from Syria. The U.S. 3rd Brigade and the 2nd Infantry Division (United States) conducted the operation with the Iraqi National Guard, Iraqi Border Police, and other Multinational Forces. The U.S. III Corps uses ‘Phantom’ as its nickname. Launched in early August 2004. [END] 
[1]  [DOC] The 2nd Infantry Division ("Indianhead"; "2ID," "2nd ID", or "Second D") is a formation of the United States Army. Its current primary mission is the defense of South Korea in the initial stages of an invasion from North Korea until other American units can arrive. There are approximately 17,000 soldiers in the 2nd Infantry Division, with 10,000 of them stationed in South Korea, accounting for about 35% of the United States Forces Korea personnel. [END] 
Answer: 
2nd Infantry Division (United States)
2nd Infantry Division (United States)