With North Korea having declared a successful end to its missile and nuclear programs on April 21st 2018, the country has developed strike capabilities putting the population centres of all potential adversaries, including the entire United States mainland, within range of its strategic nuclear arsenal. The conclusion of the country's program to develop a strategic deterrent comes 60 years after the United States first stationed nuclear weapons in South Korea directed at the north, following a unilateral withdrawal from article 13D of the armistice which ended the Korean War which had prohibited the deployment of such weapons to the peninsula by either side. It was less than a year after newly elected U.S. President Donald Trump threatened the country with total annihilation at the United Nations General Assembly. While North Korea has developed tactical ballistic missiles to strike targets across South Korea since the 1980s, a time when the country faced a vast arsenal of U.S. tactical nuclear weapons deployed south of the 38th Parallel and sought to gain some form of parity with a missile program of its own, development of a strategic arsenal capable of striking U.S. targets beyond the Korean Peninsula with nuclear force began far more recently. Following the&nbsp;end of the Cold War the&nbsp;country&nbsp;was&nbsp;seriously&nbsp;threatened by the United States, and Pyongyang feared it could be targeted much as a number of other former&nbsp;Soviet&nbsp;aligned states across the world had been with often&nbsp;devastating&nbsp;effects for their&nbsp;populations.&nbsp;North Korea was labelled a member of the Axis of Evil by the United States alongside Iran and Iraq in 2002, and Iraq was just months later invaded by a U.S. led coalition force - an illegal act of war which due to the unchallenged power of the perpetrators could not be prevented by the International community. With calls in the U.S. for North Korea to take the 'appropriate lesson' from the Iraq invasion, and with the United States actively revising Operations Plan 5030 which entailed the deployment of tactical nuclear weapons to destroy North Korean bunkers and fortifications in the event of an attack, Pyongyang's&nbsp;incentive to develop a deterrent appeared greater than ever. The U.S. Congressional Research Service’s East Asia specialist Larry Niksch concluded at this time that “regime change in North Korea is indeed the Bush administration’s policy objective.” Niksch wrote that if sanctions against the country and interdiction of its shipping did not produce the desired collapse of the government, U.S. Defence Secretary Rumsfeld was considering “a broader plan of massive strikes against multiple targets.”Facing overwhelming threats from the United States, a nuclear deterrent appeared the only effective means for the small Asian state, with a defence budget orders of magnitude smaller than that of the United States, to ensure its security. In the words of Secretary Rumsfeld, a nuclear arsenal in the hands of a small state could serve “to deter us (the United States) from bringing our conventional or nuclear power to bear in a regional crisis… ’asymmetric’ approaches can limit our ability to apply military power.” A paper published in 2000 by the highly influential U.S. neoconservative think tank Project for a New American Century (PNAC) titled Rebuilding America’s Defences similarly highlighted North Korea's motivation for developing a nuclear deterrent - stating: “Weak states operating small arsenals of crude ballistic missiles, armed with basic nuclear warheads or other weapons of mass destruction, will be in a strong position to deter the United States from using conventional force... When their missiles are tipped with warheads carrying nuclear, biological, or chemical weapons, even weak regional powers have a credible deterrent regardless of the balance of conventional forces." North Korea's calculus was clear. &nbsp;North Korea successfully tested its first nuclear weapon in 2006. Pyongyang's intention from the beginning had been to develop a compact nuclear warhead capable of being fitted onto a ballistic missile, a far more complex task than the Manhattan Project and the Soviet Union's own early nuclear weapons program had sought to achieve - with both of these programs having developed heavier and more cumbersome warheads for deployment by high payload strategic bombers rather than missiles. North&nbsp;Korea&nbsp;would conduct just five more nuclear tests, successively miniaturising the warhead while maximising the payload, so that by the end of 2017 Pyongyang was able to declare that it had successfully developed a hydrogen bomb with a warhead small enough to be mounted on a ballistic missile, with a payload of several megatons and destructive capabilities exceeding those of Fat Man and Little Boy, the bombs used by the United States on Japanese population centres in 1945, by several orders of magnitude.Able to combine a miniaturised hydrogen bomb with two intercontinental ballistic missile platforms successfully tested in 2017, North Korea had successfully developed an active strategic nuclear deterrent by the end of 2017 - which precluded the country's declaration in April the following year that the country's weapon's program was complete. There is little doubt that the program has been aimed primarily if not exclusively at deterring attacks from the United States, with Korean leader Kim Jong Un stating following a successful weapons test in September 2017 that the country's deterrent was being developed as a necessity to&nbsp;“protect destiny and sovereignty from the long-standing nuclear threats of U.S. imperialists.” With North Korea having lost an estimated 20-30% of its population during the Korean War (a death toll in the millions approximately equivalent to a 9/11 attack on the country every day for three years), the country's fear of a second war with the United States and the lengths it has gone to to prevent such an incident from occurring stemmed from its historical experience.&nbsp;Alongside the Hwasong-14 and Hwasong-15 intercontinental range platforms, North Korea also retains a number of advanced intermediate range platforms designed to strike U.S. assets across the Pacific in the event of war, and these missiles are also capable of deploying weapons of mass destruction against population centres in Guam and Japan to deter attacks by the United States and its East Asian ally. The Rodong-1 dates back to the 1980s, and has been extensively upgraded over a number of years and exported to a number of foreign clients. The platform represented the first fully indigenous ballistic missile and the first with an intermediate range in North Korea's arsenal. Other platforms include the the solid fuelled Pukkuksong-2, its submarine based variant&nbsp;Pukkuksong-1,&nbsp;and the longer ranged Musudan - the latter two which&nbsp;hold&nbsp;U.S. military&nbsp;facilities&nbsp;on Guam in their range. The successful testing of the Hwasong-12 intermediate range missile in 2017 alongside the two&nbsp;intercontinental&nbsp;range platforms proved to be a game changer for North&nbsp;Korea's&nbsp;regional strike&nbsp;capabilities, and the missile has since been dubbed 'Guam Killer.' Much like China's DF-26, the Hwasong-12 was developed almost exclusively to target U.S.&nbsp;military&nbsp;facilities on Guam in light of their importance to the&nbsp;country's&nbsp;naval and air operations across the Pacific and their vulnerability to attack. It is little&nbsp;surprise&nbsp;that both East&nbsp;Asian&nbsp;powers have taken a near&nbsp;identical&nbsp;approach given Guam's&nbsp;combination of vulnerability and importance to American operations in the region, and in light of both nations perceiving ever growing threats from the United States expanding military's deployments near their borders.&nbsp;Ultimately the success of North Korea's deterrence program marks something truly unprecedented, in that it is the first time a small state has been able to independently develop the capabilities needed to effectively deter attacks from a major superpower independently. While during the Cold War a number of states were able to deter military intervention by either the United States or the Soviet Union by relying on the protection of the other (or as per the Suez crisis relying on both to prevent a joint British and French invasion), North Korea's achievement represents an entirely new phenomenon, one which could well set a precedent for a major change in the nature international relations. With the country now largely secure from attack, a reduction in conventional military expenditure and refocusing of efforts towards economic development is likely.