Under an agreement with Washington in 1972, Seoul agreed to set its missile range ceiling at 180 km in exchange for US missile technology. Through reverse-engineering of U.S.-supplied missiles, South Korea produced two versions of a two-stage, solid-fuel SSM based on the U.S. Nike Hercules surface-to-air missile: NHK-1 (180 km/500 kg) and NHK-2 (260 kn/450 kg). (1) South Korea also produces a variant of the Honest John heavy artillery rocket (37 km/500 kg). (2)
South Korea may have had plans in the 1980s to develop nuclear weapons to deter an attack by the North. The plans were reported to have been dropped under U.S. pressure. However, the reports seem to have emanated in the form of hearsay from a South Korean opposition legislator, with no confirmation from U.S. or South Korean officials, or independent sources. (3)
North Korea test-fired its Taepodong-1 missile, with an estimated range of more than 1,300 km in August 1998. Subsequently, in 1999 Seoul asked Washington to agree to extend South Korea's missile range to 300km for deployment and to 500 km for scientific research and development. The two governments agreed in principle in November 1999 to extend Seoul's deployment range to 300km, though additional details required clarification in subsequent negotiations.