In the early stages of the Korean War, North Korean forces were able to engage the Untied States and their fast growing coalition of allies almost exclusively on the ground - with the U.S. Air Force and Navy facing little opposition in gaining uncontested control of the air and sea. While the North Korean military, numbering approximately 70,000 soldiers at the time, managed to push an enemy force over twice its size into a weeks long retreat, its inability to contest air superiority or threaten enemy warships bombarding its positions from the sea made operations considerably more difficult. Indeed, it was the U.S. Navy’s unchallenged naval dominance which was key to the success of the Inchon landing, under which tens of thousands of U.S. Marines landed behind North Korean lines. This cut off supply lines while compounding the already vast American numerical advantage, forcing the North Koreans themselves onto a retreat and thereby turning the tide of the war. The importance of controlling the air and sea have been critical to North Korea’s military doctrine ever since the end of the Korean War, and alongside country’s vast investments in what would become one of the world’s most capable anti aircraft missile networks,&nbsp;the military also begun to invest heavily in defending its vast coastlines from enemy attacks. The North Korean Navy today fields by far the largest submarine fleet in the world, which is primarily compromised of short ranged indigenously designed Sang O Class attack boats which are extremely quiet and potentially lethal when patrolling the country’s territorial waters. The country’s air force itself trains regularly to target enemy warships with overwhelming force - deploying air launched anti ship missiles such as the Silkworm capable of engaging warships at ranges of several hundred kilometres. More recently, an advanced land based long range anti ship missile platform entered service to further strengthen the defences of the country’s coasts - the Kumsong-3. The Kumsong-3, also known as the KN-19, is deployed from highly mobile tracked launch vehicles which each carry four missiles. Able to redeploy rapidly, and move off road over almost any terrain due to its tracked wheels, the mobility of the launch vehicles make seeking out and destroying KN-19 missiles extremely difficult for enemy aircraft - particularly when operating under pressure from North Korean air defences. Indeed, even in the open desert terrain of the Middle East the U.S. Air Force had trouble hunting down the far larger and more conspicuous mobile Scud missile launchers used by Iraq during the 1991 Gulf War - and when operating in forested or mountainous terrain the Kumsong-3 is likely to prove considerably more survivable still. Able to ”˜shoot and scoot,’ the missiles are able to inflict considerable damage to enemy warships at extreme ranges and quickly relocate to avoid being located and destroyed. With North Korea’s terrain being the most extensively tunnelled in the world according to a number of reports, missile batteries may well even be able to disappear underground to avoid detection by enemy forces - striking at the opportune moment before again disappearing. The missile can thus significantly enhance the country’s costal defence network. The Kumsong-3 is, according to a number of Western sources, derived from the Russian Kh-35 anti ship cruise missile, though these claims have yet to be verified. While the missile system has previously been sited during military parades, a demonstration of its capabilities in June 2017 was met with much apprehension among North Korea’s potential adversaries. The Kumsong-3 is in fact significantly more capable than the standard Kh-35, and contains important evolutionary guidance and manoeuvrability improvements making it both more precise and more difficult to intercept despite its subsonic speeds. According to U.S. sources, the missile test carried out in mid 2018 demonstrated successful waypoint manoeuvres and a considerable in flight at a range of at least 240 kilometers - as well as a more advanced guidance suite in its seeker than the Kh-35. Seekers reportedly made use of sophisticated active radar and infrared homing for terminal guidance. With the Kh-35 having entered Russian service in 2003, and today considered the country’s most capable subsonic anti ship cruise missile, the fact that the Korean platform can surpass its capabilities bodes ill for the country’s potential adversaries. During the June 2017 combat test, Kumsong-3 missiles were launched from Wonsan to strike a target near Mayang Do island. The missiles demonstrated the advanced capabilities of their guidance systems, flying into the Sea of Japan perpendicular to the coast, further east than the location of the target, before turning at low altitude to minimise chances of detection. The missiles proceeded to turn towards the target and launch a successful strike. The platforms’ high manoeuvrability and resulting survivability against ship based missile defences was demonstrated adequately. The assessment, as reported by Western sources, align with those of North Korea - with Korean state broadcaster KCNA reporting: “the launched cruise missiles accurately detected and hit the floating targets on the East Sea of Korea after making circular flights.” Maps indicate that the precise location of waypoint at which the missiles changed course was preplanned. The ability of the missiles to successfully carry out in flight waypoint manoeuvring makes them a lethal threat to the U.S. Navy and the surface warships of other potential adversaries near Korean coasts. Combined with heavily fortified coastal radar arrays, the missiles would provide the North Korean military with the ability to strike hostile targets hundreds of miles out to sea with impunity. The Kumsong-3 represents one of several highly sophisticated asymmetric weapons systems North Korean has invested heavily in developing to be able to effectively deter hostile attacks, and the missile’s testing came at a time of peaking tensions between the country and the United States. Much like neighbouring China has done with its own anti ship missile platforms, in the face of a growing threat from the U.S. Navy, North Korea is also likely to continue to invest in improving the range and accuracy of the Kumsong-3 - a highly cost effective means of protecting the country’s coasts from hostile attacks. In this way, that country can avoid ceding undisputed control of the surrounding seas to the United States as it did in the Korean War - meeting an enemy attack on land, in the air as well as at sea and thereby posing a far greater threat to a potential attacker than it did during the previous war.