Question: Who directed a 2004 Korean horror film set in 1972 Vietnam, during the Vietnam War, that stars a South Korean actor known for his role in action films?

Context articles: The Boys in Company C
Easter Offensive
Edwin B. Hooper
Son Byong-ho
Dead Friend
Missing in Action (film)
Koreans in Vietnam
Face (2004 film)
Death Bell
R-Point

The Boys in Company C, directed by Sidney J. Furie, starring Stan Shaw, Andrew Stevens, Craig Wasson, James Canning, and Michael Lembeck, is a 1978 film about United States Marine Corps recruits preparing for duty, and their subsequent combat in the Vietnam War.
 It was among the first Vietnam War films to appear after the Vietnam Era, and was also the first role for R. Lee Ermey of "Full Metal Jacket" fame.
 "The Boys in Company C" is the first in Furie's Vietnam War motion picture trilogy, followed by 2001's "Under Heavy Fire" and 2006's "The Veteran".
The Easter Offensive (Vietnamese: Chiến dịch Xuân hè 1972, or Mùa hè đỏ lửa, the "Red fiery summer" as romanticized in South Vietnamese literature) was a military campaign conducted by the People's Army of Vietnam (PAVN, the regular army of North Vietnam) against the Army of the Republic of Vietnam (ARVN, the regular army of South Vietnam) and the United States military between March 30 and October 22, 1972, during the Vietnam War.
 This conventional invasion (the largest offensive operation since 300,000 Chinese volunteers had crossed the Yalu River into North Korea during the Korean War) was a radical departure from previous North Vietnamese offensives.
 The offensive was not designed to win the war outright but to gain as much territory and destroy as many units of the ARVN as possible, to improve the North's negotiating position as the Paris Peace Accords drew towards a conclusion.
Edwin Bickford Hooper (February 26, 1909 – September 12, 1986) was a vice admiral of the United States Navy—his Naval service spanned 5 decades from 1930 to the 1970.
 He served in World War II, Korean and Vietnam Wars and made important contributions to gunnery, ship operations, ordnance, amphibious operations, military logistics and study of naval history.
 He directed the gunfire in an important battleship-against-battleship action in 1942; was involved in the early days of United States Atomic Energy Commission; established the Navy's long range study group; lead the Service Force during the Vietnam war; and was the Navy's Historian—writing several Navy histories including the first volume on the Vietnam War.
Son Byong-ho (born August 25, 1962) is a South Korean actor.
 Son is known for his role in action films, notably, "R-Point" (2004), "Running Wild" (2006), "The Good, the Bad, the Weird" (2008) and Queen Insoo (2011).
Dead Friend (; lit.
 "The Ghost") is a 2004 South Korean horror film.
 It is one of a number of South Korean horror films set in high school; the trend began with 1998's "Whispering Corridors".
Missing in Action is a 1984 American action film directed by Joseph Zito and starring Chuck Norris.
 It is set in the context of the Vietnam War POW/MIA issue.
 Colonel Braddock, who escaped a Vietnamese prisoner of war camp 10 years earlier, returns to Vietnam to find American soldiers listed as missing in action during the Vietnam War.
 The film was followed by a prequel, "" (1985), and a sequel, "" (1988).
Koreans in Vietnam is a community of Vietnam with a population of Korean expatriates along with Vietnamese citizens of Korean ancestry.
 The population initially came in a military capacity, fighting on both sides of the Vietnam War.
 After the end of the war, there was little Korean migration or tourism in Vietnam, until the rise of the South Korean economy and the decline of the North resulted in an influx of South Korean investors and North Korean defectors, as well as South Korean men seeking Vietnamese wives.
 As of 2011, according to statistics of South Korea's Ministry of Foreign Affairs and Trade, they numbered roughly eighty thousand people, making them the second-largest Korean diaspora community in Southeast Asia, after the Korean community in the Philippines, and the tenth-largest in the world.
 A more recent estimate from Vietnam Television says their population might be as large as 130,000.
Face is a 2004 Korean horror film directed by Yoo Sang-gon.
Death Bell () is a 2008 South Korean film.
 The only Korean horror film released over the summer of 2008, it is the first feature by former music video director Chang (real name Yoon Hong-seung), who also co-wrote the screenplay.
 "Death Bell" stars Lee Beom-soo in his first horror film role, and K-pop singer Nam Gyu-ri in her acting debut.
 Set in a Korean high school, the film's native title refers to "gosa", the important midterm exams that all students are required to sit.
R-Point () is a 2004 Korean horror film written and directed by Kong Su-chang.
 Set in 1972 Vietnam, during the Vietnam War, it stars Kam Woo-sung and Son Byong-ho as members of the South Korean military in Vietnam.
 Most of the movie was shot in Cambodia.
 Bokor Hill Station plays a prominent part of the movie, in this case doubling as a colonial French plantation.