<Li> May 1980: North Koreans engage OP Ouillette on DMZ in firefight . One North Korean WIA . </Li> <Li> March 1981: Three North Koreans try to enter the South in Geumhwa - eup, Cheorwon, Gangwon - do; one is killed . </Li> <Li> July 1981: Three North Koreans are killed trying to cross the Imjin River to the South . </Li> <Li> November 1984: Nine North Korean soldiers and one South Korean soldier die, and one American soldier is wounded during the firefight that erupted when a North Korean security detail chased a defecting Soviet citizen (Vasily Matusak) across the MDL into the southern - controlled sector of the Joint Security Area . </Li>

How many u.s. troops are in south korea