South Korea’s Covert Operations in North Korea
After Pyongyang attacked Seoul in the late 1960s, the South counterattacked
In the late 1960s, North Korea unleashed a guerrilla war on South Korea, sending spies and special operations troops across the Military Demarcation Line that separates the two countries in an attempt to cause havoc in the backyard of its rival.
The highlights of Pyongyang’s campaign have since become well known — the attempted assassination of Pres. Park Chung-hee in Seoul, the landing of 120 commandos along the South Korean coast and the infiltration of agents into the Republic of Korea.
Less well-known, however, is the fact that South Korea responded to the attacks with a covert war of its own. Almost from the very beginning of Kim Il-sung’s campaign, South Korean forces retaliated against the North with raids and intelligence missions that ventured across the MDL into North Korean territory.
South Korea has been hesitant to say much about the operations, but some details have come to light.
In 2011, Rep. Lee Jin-sam, a South Korean general and an ROK legislator, toldKorea Times that the South had carried out attacks on roughly 50 North Korean facilities in 1967.  Other lawmakers have said that South Korea sent as many as 7,700 people into North Korea from the end of the Korean War until 1972, the majority of whom never made it back. 
But those aren’t the only sources of information on South Korea’s operations in North Korean territory. Declassified U.S. State Department and CIA documents from the National Archives, which War Is Boring reviewed, shed new light on the ROK’s late-1960s adventures across the MDL.
Read the Remainder at War is Boring