How much missile range is needed to hit any part of North Korea from the south? All of the Democratic People's Republic is within about 500 km (300 mi.) of the border, so, even allowing for deployment behind lines and evasive routing, 1,000 km should be plenty.

Yet South Korea has confirmed it has a cruise missile that will fly farther than that. Indeed, well-sourced local media reports give the range of the weapon as 1,500 km.

The Tomahawk-like cruise missile, which must be the previously reported Hyunmu 3C, has world-class precision, good enough to fly through a window, says Maj. Gen. Shin Won-sik, director general of planning at the defense ministry, who did not name the weapon.

Another bombardment missile whose deployment he acknowledged is presumably the ballistic Hyunmu 2B. It is superior to the Lockheed Martin MGM-140 Army Tactical Missile System (Atacms), and can fly 300 km, Shin says. The Chosun Ilbo newspaper says the weapon is capable of 500 km but is restricted to 300 km to comply with South Korea's commitment to the U.S. not to deploy ballistic missiles with greater range. The agreement also limits South Korean ballistic missile warheads to 500 kg (1,100 lb.).

It is unusual for the South Korean military to discuss missile programs, as Shin now has. However, considerable details of land-attack missiles have been leaked in fragmentary local media reports over the years. Sifted and collated, they together reveal a startlingly ambitious and apparently successful development effort—while acknowledging the existence of foreign help, but not its source.

Russia or other former members of the U.S.S.R. seem to be likely partners. South Korea is relying on Russian technology for its space-launcher program. Hyunmu 2 looks much like the Russian Iskander short-range ballistic missile, one version of which can reach 500 km.

Three South Korean surface-to-surface cruise missiles are known from the news leaks: Hyunmu 3A, 3B and 3C, with ranges of 500, 1,000 and 1,500 km, respectively. A fourth, under development, is supersonic, though it is unclear whether it is intended for land attack. A supersonic anti-ship missile is also known. Further improvements in range and accuracy of the land-attack weapons are reportedly planned.

Hyunmu 3B is supposed to have entered service in 2009. The 3C was reportedly deployed in 2010 and, according to a leaked U.S. diplomatic cable, was tested at least as early as 2006. The short deployment lag behind the 3B, just one year, suggests that the 3C is closely related to its immediate forebear, which the Yonhap news agency has described as an upgrade of the 3A. A test of the 3B was revealed in 2006.

Almost all of Japan and many of China's largest cities, including Beijing and Shanghai, are within 1,500 km of South Korea, indicating the regional capability that Seoul is seeking with the cruise missile program.

Hyunmu 3C weighs 1.5 tons, is 6 meters (19.7 ft.) long and 53-60 cm in diameter, carries a 450-kg warhead and flies at slightly less than Mach 1, Chosun Ilbo reported in 2010, quoting a military officer. It is supposed to have an accuracy of 1-2 meters while Hyunmu 3B is accurate to 5 meters with terrain-comparison guidance. The 3C uses GPS for guidance, the ministry tells KBS television. Conceivably, both technologies could be employed.

Like the Tomahawk, Hyunmu 3C has reportedly been designed for launch from submarines and surface ships, but South Korea has deployed a naval land-attack missile called Cheonryong that has a range of more than 500 km; it may be a modified 3A.

South Korea will deploy a supersonic successor to its Haeseong 1 ship-to-ship missile under the designation Haeseong 2, a foreign ministry official has revealed. That missile was tested as early as 2007, according to a leaked cable. South Korea told the U.S. then that the weapon had a mass at the beginning of its cruise phase of 1.28 metric tons, including 270 kg of fuel, and an empty mass of about 1 ton. The engine had a thrust of 800 lb. and burned 0.8 lb. of fuel per lb.-thrust per hour.

South Korea's great effort in cruise land-attack missiles may stem from treaty limits on the range of its ballistic missiles. Its first ballistic bombardment missile was Hyunmu 1 of the 1980s, derived from the U.S. Nike-Hercules surface-to-air missile, but Hyunmu 2 is quite different. Hyunmu 2 (perhaps Hyunmu 2A) entered service in 2008 and 2B in 2009.

“Hyunmu” is the name of a mythical creature that defends the northern skies.