Operation Napoleon/Saline was a multi-Battalion operation conducted by the United States Marine Corps and the United States Army along the Cửa Việt River south of the DMZ in Quảng Trị Province. The operation ran from 20 January to 9 December 1968.

3rd Battalion, 3rd Marines, abbreviated as (3/3), was an infantry battalion of the United States Marine Corps, based out of Kaneohe, Hawaii. Known as either "Trinity" or "America's Battalion", the unit normally fell under the command of the 3rd Marine Regiment of the 3rd Marine Division. When fully manned, the unit consisted of approximately 1000 U.S. Marines and United States Navy Sailors. Like most 20th century model infantry battalions of the U.S. Marine Corps, 3rd Battalion 3rd Marines was made up of three rifle companies, Weapons Company and a Headquarters and Services (H&S) company. The battalion was originally formed at Marine Corps Base Camp Lejeune, North Carolina in 1942 and saw action on both Bougainville and Guam during World War II, where it was awarded its first Presidential Unit Citation and Navy Unit Commendation. Marines in the battalion were also awarded one Medal of Honor and seven Navy Crosses during the war.