Capabilities:

South Korea has a series of short-range ballistic missiles based on the Nike Hercules design. Additionally, it deploys two series of cruise missiles, known as the Haesong and Hyonmu with ranges that could potentially reach ~1,500km.[1] While South Korea no longer possesses WMD, these missiles can carry WMD payloads.

History:

In 1954, the United States and South Korea signed the ROK/U.S. Mutual Security Agreement, codifying their intent to defend each other against outside aggression. However, when Pak Jung-hee came to power in a surprise military coup, relations with Washington became strained. Pak embraced a policy of “self-reliance” in national defense through the 1960s and 1970s. Unease about the U.S. commitment to the Mutual Security Agreement under Nixon and later Carter in part played into his goal of building a missile program.[2]

Ballistic Missiles

President Pak Jung-hee issued a confidential order to develop a missile program to his cabinet in 1971. In the following year, the Ministry of National Defense gave the Agency for Defense Development (ADD) an official order to develop short-range tactical missiles and long-range surface to surface missiles under the project name “Aerospace Industry Project” (항공공업계획).[3] In 1972, Seoul and Washington agreed to an arrangement that allowed South Korea to reverse-engineer Nike Hercules surface-to-air missiles in exchange for limiting the range to 180km and the payload to 500kg. South Korea ultimately built two systems based on this design known as the NHK-1 and NHK-2.[4]

South Korea’s Aerospace Industry Project accelerated in earnest in 1975 as it is incorporated the “Yulgok Plan” aimed at reducing the military gap between North and South Korea. The Agency for Defense Development collaborated on missile design with McDonnell Douglas, acquired a propellant plant from Lockheed Corporation, and signed an agreement for propellant technology and raw materials with France’s SNPE in 1975.[5]

In 1978, after three missile tests, South Korea successfully demonstrated the NHK-1 (K-1, Baekgom, 백곰) surface to surface missile with a range of 180km and 500kg payload.[6] The Baekgom design had a defect in that it was susceptible to jamming signals and electromagnetic waves. In 1978, the ADD acquired an inertial navigation system from Ferranti for the NHK-2 (K-2, Hyonmu 1, 현무 1) to overcome these shortcomings, and improved first stage propulsion system in order to avoid separation failure.[7]

In 1979, the previous 1972 agreement was elevated to a government-level memorandum endorsed by the President and Minister of National Defense.[8] The U.S. was wary of the Agency for Defense Development (ADD) and its attempts to secretly start a nuclear program under Pak.[9] The guidelines allowed for American technology procurement in exchange for strict adherence to the 1972 limits on range and payload.[10] In a move to bolster legitimacy and assuage the U.S. fears, the new military regime after Pak's assassination decided to slash the missile development program by firing over thirty executive officials of the ADD.[11]

After a 1983 assassination attempt by North Korea, President Chun Doo-hwan ordered the Agency for Defense Development to complete the Hyonmu by the 1988 Seoul Olympics.[12] It did so on 21 September 1985 with the first of three successful tests of the Hyonmu before President Chun put the missile into operation in 1987.[13] The range and payload of the Hyonmu are 180km and 500kg respectively. The Hyonmu is an upgraded version of the Baekgom in terms of versatility, given that the Hyonmu can be topped with either a single high-explosive or cluster munitions warhead. According to the 1990 U.S. inspection of the Hyonmu, it complied with range and payload restrictions; however it is possible the range could have been extended to 250km (beyond the agreed-upon 180km) by 1999.[14] Two hundred Hyunnmu-1 were deployed in two battalions, but currently the Hyunmu-1 is stored in a reserve force since its replacement by the Hyunmu-2.[15]

In the early 1990s, North Korea began testing and eventually deployed the 1,000km-range Nodong missile. Seoul sought to renegotiate the guidelines, pointing to the threat of North Korea, however the U.S. was reticent to expand on the current guidelines, and continued to enforce export controls in accordance with the 1979 terms. At the same time President Roh Tae-woo began to warm relations with South Korea's former adversary, the Soviet Union, with $3 billion in loans and trade credits.[16] After signing a bilateral military cooperation agreement with Russia in 1992, South Korea began to focus on ballistic missile and space launch vehicle technology exchange using “Operation Siberian Brown Bear (불곰사업)” through South Korea’s Defense Acquisition Program Administration (DAPA).[17] There were clandestine acquisitions from Russia as well, according to a South Korean businessman who reportedly moved to Petropavlovsk-Kamchatsky, Russia where he won a contract to recover scrap metal from decommissioned START I Treaty ICBMs. He reportedly acquired enough parts for one ICBM, including two missile engines.[18]

The U.S. initially opposed South Korea joining the MTCR. However, after 20 rounds of talks starting in 1995, Washington and Seoul agreed to set new ballistic missile guidelines, wherein Seoul would join the MTCR in March 2001 and the parties would revise the missile range and payload guidelines up to 300km and 500kg respectively.[19] Throughout the process, Washington insisted that:

1. “The U.S. would have the right to inspect missile production facilities;
2. The ROK would have to provide information at each step prior to research, development, production, and deployment;
3. The ROK could not conduct research on missile systems with a range greater than 300km; and
4. [The] ROK would have to disclose information on civilian rocket research.”[20]

South Korea developed the NHK-2 PIP B (Hyunmu-2B) with the goal of improving accuracy. The technologies of Russia’s SS-21 were adapted, reducing the weight of the warhead to 300kg, and increasing the range to 500km; the addition of a mobile launcher increases survivability.[21] According to leaked cables, the Hyunmu-2B went into production in 2005, and 51 were produced between 2009 and 2011.[22] South Korea has deployed the Hyunmu-2B on its central and eastern borders since the end of 2009.[23]

On 7 October 2012, Seoul and Washington yet again agreed to revise missile guidelines allowing a missile range of up to 800km. The guidelines for payload remain at 500kg, but under the “trade-off” article, the payload can be increased in inverse proportion to range.[24] South Korea’s National Security Adviser, Chun Yung-woo, announced "if North Korea is to attack or provoke, we are able to incapacitate its nuclear and missile (capabilities) in the early stage. We have guaranteed various capabilities to protect the life and safety of our people."[25]

The new missile guidelines are controversial. South Korea's missiles can now reach all parts of North Korean territory, including its long-range missile bases and the nuclear facilities at Yongbyon. However, medium-range ballistic missiles are neither likely to deter attacks such as those on the Cheonan or the shelling of Yeonpyeong Island, nor are they effective against North Korea’s mobile missile forces.[26] Furthermore, Jeffrey Lewis argues the increased range could contribute to tensions in Northeast Asia, and is a blow to the nonproliferation community.[27]

Cruise Missiles

Seoul began to focus on cruise missile development in the 1990s, because that they were not subject to the same range restrictions as ballistic missiles, and offered improved accuracy and flexibility on the battlefield.[28]

South Korea’s first cruise missile was the SSM-700K (Haeseong). The project began in 1996 to replace the RGM/AGM-84 Harpoon, and the Agency for Defense Development (ADD) officially announced its Haeseong development project in 1998.[29] The Haeseong was first displayed in 2003, and it went into regular production in 2006. The Haeseong is an anti-ship missile with range of 200km. South Korea began development of the Haesong-2 in 2010.

South Korea developed the Hyonmu series as a land-attack missile based on the Tomahawk. Hyonmu-3 is categorized into three types: -A, -B, and -C, according to range. Hyonmu-3A is a ground launched cruise missile, with a maximum range of 500km.[30] These were deployed in the central part of the Korean Peninsula since the beginning of the 2000s.[31] The Hyonmu-3B and -3C use more efficient turbofan engines, and can fly up to 1,000km, and 1,500km respectively. The first test of Hyonmu-3B was reported in 2006, and it has been deployed since 2009.[32]

As of 2012, South Korea is developing a ship-to-land version of the Haesong missile with an inertial navigation system and infrared imaging sensors instead of radar.[33] It is expected to be tested in 2015.[34] Separately, South Korea is expected to develop a supersonic anti-ship/-land cruise missile within the Haeseong series.[35] The Hyonmu-3C program is in testing, and it is expected to be deployed between 2012 and 2013.

Dual-Use Space Launch Vehicles

The Baekgom and Hyunmu-1 programs gave impetus to South Korea's scientific rocket development program. The Korea Aerospace Research Institute (KARI) launched its first research rocket, Korea Sounding Rocket-1, a single stage solid fuel rocket, in 1993. Five years later KARI launched its second research rocket, KSR-2, which is a two stage solid propellant rocket. In 2002, KARI succeeded in testing its first liquid propellant single stage rocket, the KSR-3.[36] Following these initial tests, South Korea implemented a program for its first space launch vehicle, the Korea Space Launch Vehicle (KSLV), also known as Naro. In 2004, Seoul and Moscow signed an agreement for aerospace technology cooperation, which was followed up with a technology safeguards agreement in 2006.[37]

The KSLV-1 is a two stage space launch vehicle (SLV), which can reach a 300km orbit at 38 degrees with a 100kg payload.[38] South Korea expected co-development of the first stage propellant, but this was restricted by its technology safeguards agreement with Russia, which only shared know-how on launch pad design and operation. Negotiations dragged on, ultimately delaying the first launch.[39] South Korea developed an indigenous kick motor for the second stage of the KSLV-1.[40]

The first KSLV-1 test failed in 2009 due to a separation failure. The following year, a second test also failed when the first stage propellant exploded 137 seconds after its launch. A third test was scheduled for 29 November 2012; however, the test was delayed hours before launch due to a technical malfunction.[41] In January 2013, South Korea successfully placed a satellite into orbit using the KSLV-1.[42]

South Korea is now developing an indigenous KSLV-2 rocket. The KSLV-2 consists of three stages for a 1.5 metric ton payload, and a potential altitude of 600-800km. KARI plans to test the first two stages in 2018, and if successful, the three stage space launch vehicle in 2021.[43]

Recent Development and Current Status

2012 was a year of continuing tensions between North and South Korea. North Korea announced that it would launch its Unha-3 rocket to put a satellite into orbit on 12 April 2012. Though the launch failed, it was widely seen as a chance to test long-range missile technology. On 19 April 2012, South Korea’s President Lee Myung-bak made a public visit to the Agency for Defense Development, and the Ministry of National Defense released video footage of the Hyunmu-2 ballistic missile and the Hyunmu-3 cruise missile.[44] Dan Pinkston, points out that based on the footage, the missiles may have been based on the designs of the Russian Iskander (SS-26) and Iskander-K.[45] In the footage, the Hyunmu-3 cruise missile flies into a target that resembles a Korean palace. Shin Won-sik a Defense Ministry official told reporters that “This cruise missile can attack a target as small as a window located hundreds of kilometers away.”[46] The same day, Kim Jong Un and much of the North Korean leadership visited Kumsusan Palace to honor founding father Kim Il Sung’s memory.[47]

Sources:
[1] Gwak Chang-ryul, "사정거리 1,500km 國産 크루즈 미사일 실전배치 [Indigenous Cruise Missile of 1,500km Range Deployed],” Chosun Ilbo, 17 July 2020, http://news.chosun.com.
[2] Chung Yong-soo, "Special knowledge <400> 방위사업 40년 [40 Years of Defense Industry]," Joongang Daily, 12 January 2012, http://article.joinsmsn.com.
[3] Koo Sang-Hoi, “한국 미사일 개발의 산 증인 구상회 박사 회고(1) [Reminiscence from a Living Witness of the Korean Missile Program, Dr. Koo Sang-hoi],” Shindonga, February 1999, www.donga.com.
[4] Koo Sang-Hoi, “한국 미사일 개발의 산 증인 구상회 박사 회고(1) [Reminiscence from a Living Witness of the Korean Missile Program, Dr. Koo Sang-hoi],” Shindonga, February 1999, www.donga.com; “South Korea,” Federation of American Scientists, 3 February 2000, www.fas.org; Oh Won-chul, 한국형 경제건설 [Korean Economic Construction Model] (Seoul, CEOI, 1996)  p. 560.
[5] Oh Won-chul, 한국형 경제건설한국형 경제건설 [Korean Economic Construction Model] (Seoul, CEOI, 1996) p. 563.
[6] Kim Byung-ki, “포착 10분 이내 북한 미사일 기지 격파하라 [Destroy North Korea’s Missile Base within 10 Minutes of Detection],” Shindonga, 25 September 2012, http://news.naver.com.
[7] Oh Won-chul, 한국형 경제건설한국형 경제건설 [Korean Economic Construction Model] (Seoul, CEOI, 1996) p. 580.
[8] Kim Hak-Jin, "'北 미사일 억지력' 길을 찾아야 [South Korea Should Have Missile Deterrence Against North Korea]," Donga Ilbo, 7 October 2009, http://news.donga.com.
[9] Don Oberdorfer, The Two Koreas: A Contemporary History (Indianapolis, Basic Books, 2001) pp. 68-74.
[10] Daniel Pinkston, “The New South Korean Missile Guidelines and Future Prospects for Regional Stability,” Strong & Prosperous, International Crisis Group, 25 October 2012, www.crisisgroup.org.
[11] Lee Eun-young, "ADD 무기개발 3총사의 핵, 미사일 개발 비화 [The ADD Trio’s Secret Story of Nuclear and Missile Development]," Shindonga vol. 567, 2006, pp. 276-287.
[12] Cha Young-gu, 국방정책의 이론과 실제 [Principle and Reality of Defense Policy] (Seoul, Oleum, 2002) p. 89.
[13] Koo Sang-Hoi, “한국 미사일 개발의 산 증인 구상회 박사 회고(1) [Reminiscence from a Living Witness of the Korean Missile Program, Dr. Koo Sang-hoi],” Shindonga, February 1999, www.donga.com.
[14] Yoo Yong-won, “|무기의 세계| 한국군 탄도 미사일 대표 주자 현무 미사일 [Korea’s Foremost Ballistic Missile, Hyunmoo],” Navercast, 16 April 2012, http://navercast.naver.com; Kim Do-hyung, “한-미 미사일시험 논란 [U.S. - Korea Missile Tests and Controversy]," Hankyoreh, 20 April 1999, http://m.hani.co.kr.
[15] Kim Byung-ki, “포착 10분 이내 북한 미사일 기지 격파하라 [Destroy North Korea’s Missile Base within 10 Minutes of Detection],” Shindonga, 25 September 2012, http://news.naver.com.
[16] Daniel Pinkston, “The New South Korean Missile Guidelines and Future Prospects for Regional Stability,” Strong & Prosperous, International Crisis Group, 25 October 2012, www.crisisgroup.org.
[17] Daniel Pinkston, “The New South Korean Missile Guidelines and Future Prospects for Regional Stability,” Strong & Prosperous, International Crisis Group, 25 October 2012, www.crisisgroup.org.
[18] Gang Hun, “[Why] 어느 사업가의 고백 ‘내가 ICBM (대륙간 탄도미사일)한국에 들여왔다[[Why] A Businessman’s Confession: I brought South Korea an ICBM],” The Chosun Ilbo,  25 June 2011, http://news.chosun.com; Daniel Pinkston, “The New South Korean Missile Guidelines and Future Prospects for Regional Stability,” Strong & Prosperous, International Crisis Group, 25 October 2012, www.crisisgroup.org.
[19] Daniel Pinkston, “The New South Korean Missile Guidelines and Future Prospects for Regional Stability,” Strong & Prosperous, International Crisis Group, 25 October 2012, www.crisisgroup.org.
[20] Daniel Pinkston, “The New South Korean Missile Guidelines and Future Prospects for Regional Stability,” Strong & Prosperous, International Crisis Group, 25 October 2012, www.crisisgroup.org.
[21] Kim Byung-ki, “포착 10분 이내 북한 미사일 기지 격파하라 [Destroy North Korea’s Missile Base within 10 Minutes of Detection],” Shindonga, 25 September 2012, http://news.naver.com.
[22] Kim Byung-ki, “포착 10분 이내 북한 미사일 기지 격파하라 [Destroy North Korea’s Missile Base within 10 Minutes of Detection],” Shindonga, 25 September 2012, http://news.naver.com.
[23] Oh Dong-yong, “[특종] 사거리 500km 국산 탄도미사일 ‘현무-2B’ 실전배치했다! [[Exclusive Report] Hyonmu 2-B with 500km Range is Deployed],” The Chosun Monthly, no. 3, 2011, http://monthly.chosun.com.
[24] Sang-Hun Choe, “U.S. Agrees to Let South Korea Extend Range of Ballistic Missiles,” The New York Times,
 7 October 2012, www.nytimes.com.
[25] KJ Kwon, “South Korea Says U.S. Agrees to Extend Seoul’s Ballistic Missile Range,” CNN, 7 October 2012, www.cnn.com.
[26] Jeffrey Lewis, “RoK Missile Rational Roulette,” Arms Control Wonk, 9 October 2012, http://lewis.armscontrolwonk.com.
[27] Jeffrey Lewis, “Missiles Away!,” Foreign Policy, 9 October 2012, www.foreignpolicy.com.
[28] Office of the President of the Republic of Korea, Cheong Wa-dae, “한미 미사일 지침 개정 주요 내용 및 의미,기대효과 [The Significance and Expected Effect of The Revision of The Missile Agreement Between Korean and U.S.],” 23 October 2012, www.president.go.kr/kr/podcasts/main_banner/bluehouse135.pdf.
[29] “Hae Seong (SSM-700K),” Jane’s Strategic Weapon Systems, 18 October 2012.
[30] “Hyonmu 3,” Jane’s Strategic Weapon Systems, 28 September 2012.
[31] “Hyonmu 3,” Jane’s Strategic Weapon Systems, 28 September 2012.
[32] “Hae Seong (SSM-700K),” Jane’s Strategic Weapon Systems, 18 October 2012.
[33] “Hae Seong (SSM-700K),” Jane’s Strategic Weapon Systems, 18 October 2012.
[34] Kim Byung-ki, “포착 10분 이내 북한 미사일 기지 격파하라 [Destroy North Korea’s Missile Base within 10 Minutes of Detection],” Shindonga, 25 September 2012, http://news.naver.com.
[35] Kim Byung-ki, “포착 10분 이내 북한 미사일 기지 격파하라 [Destroy North Korea’s Missile Base within 10 Minutes of Detection],” Shindonga, 25 September 2012, http://news.naver.com.
[36] “KSR 3 [Korea Surrounding Rocket 3],” Doosan Encyclopedia, http://terms.naver.com.
[37] “우여곡절 나로호 [Naro-ho in Complications],” Hankyoreh, 29 November 2012, www.hani.co.kr.
[38] Rui C. Barbosa, “South Korea Launch of KSLV-1 – Russia Claims it Failed,” NASA Spaceflight, 25 August 2009, www.nasaspaceflight.com.
[39] Hyong-ki Park, “Glitches do not Deter Korea’s Space Program,” The Korea Herald, 29 November 2012, http://khnews.kheraldm.com.
[40] “<마지막 도전, 나로호> 한-러 공동개발 발사체[<Last Challenge, Naro-ho> Space Launch Vehicle Co-Developed by Korea and Russia],” Yonhap News, 27 November 2012, http://news.naver.com.
[41] Chung Yeon-ok, “나로호 발사 또 연기, 내일부터 정밀 점검 [Naro Launch Delayed, Inspection Tomorrow],” KBS, 30 November 2012, http://news.kbs.co.kr.
[42] Jung-yoon Choi and Barbara Demick, "South Korea launches satellite into orbit," The Los Angeles Times, 30 January 2013, http://www.latimes.com.
[43] Lim So-hyung, “국산 우주발사체 KSLV-2, 2018년 첫 시험 발사한다 [The First Test Launch of the KSLV-2 Will be in 2018],” Hankook Ilbo, 31 May 2011, http://news.hankooki.com.
[44] Footage from KBS (Korean).  “South Korea-Ballistic Missile & Cruise Missile,” 19 April 2012, via: www.youtube.com.
[45] Daniel Pinkston, “The New South Korean Missile Guidelines and Future Prospects for Regional Stability,” Strong & Prosperous, International Crisis Group, 25 October 2012, www.crisisgroup.org.
[46] Kim Hee-jin, “South Shows off Missiles of its Own,” JoongAng Daily, 20 April 2012, http://koreajoongangdaily.joinsmsn.com.
[47] “Kim Jong Un Has Photo Session with Participants in Military Parade,” KCNA, 20 April 2012, www.kcna.co.jp.