‘Without America, we would not be here’, said a talkative taxi driver during my recent visit to Seoul. On 25 June, the country commemorated the 75th anniversary of the beginning of the Korean War, in what will go down in history books around the world – albeit not in North Korea – as the unfinished conflict. It was, as Max Hastings argues, ‘the first war [the West] could not win’. According to North Korea, it was a war in which it struck a ‘decisive victory’.

Seventy-five years after Kim Il Sung’s invasion of South Korea, there is no clearer sign of the war’s indelible legacy than the division of a once-unified peninsula along the Demilitarized Zone. Year after year, South Korea commemorates the war by rightly stressing its ‘blood-forged’ alliance with the United States, while North Korea takes the opportunity to chastise the US ‘imperialists’, who it deems to have started the conflict. The war epitomised just how quickly the Korean Peninsula would become embedded in a tragedy of great-power politics. For as long as this remains, these memories will not die.

Near Seoul’s Gwanghwamun Square, photographic displays of the Korean War abound. For the United Nations Command that fought in the peninsula between 1950 and 1953 – comprising South Korea; 16 additional countries that provided troops (including the United States, the United Kingdom, and Australia); and five that contributed humanitarian support – the war was a battle for freedom, peace, and democracy against the antithesis of these values expounded by the communist North Korea and its Soviet and Chinese partners.

Following Japan’s formal surrender in the Second World War on 2 September 1945, the temporary division of the Korean Peninsula along the 38th Parallel saw the Soviet Union administer the northern half and the United States its southern counterpart. After North and South Korea became two separate states in 1948 – under the respective leaderships of Kim Il Sung and Syngman Rhee – the two soon-to-be Cold War superpowers withdrew their forces from their respective Koreas.

Troop withdrawal, however, did little to ease inter-Korean tensions. For the impatient Kim Il Sung, the opportunity to invade South Korea and unify the peninsula under communist rule was a long-time ambition. Indeed, North Korean history books continue to perpetuate the myth that, while he was in Manchuria during the 1930s and early 1940s, he single-handedly led a revolution for Korean independence against Japan.

Nonetheless, numerous attempts to convince his Soviet and Chinese patrons to approve his invasion had been rebuffed. For Mao, communist victory in the Chinese Civil War in December 1949 ushered in a more urgent task of consolidating power. The Soviet Union, too, initially discouraged Kim’s invasion out of fear that a Soviet-US conflict could ensue, considering Washington’s likely assistance to Seoul in the event of war.

Such concerns, however, did little to assuage Kim Il Sung. Stalin eventually relented, having been falsely assured by Kim that any conflict would be over quickly; the South Korean people would support the North; and Washington would abstain from involvement. None of these predictions came true.

In January 1950, the then-United States Secretary of State, Dean Acheson, declared that the United States’s defence perimeter ‘runs along the Aleutians to Japan and then goes to the Ryukyus’, to the exclusion of Taiwan and Korea. These words would have been leveraged by Kim to support his pleas to Stalin, but Acheson’s rhetoric did not prevent Washington’s eventual involvement in the ensuing war as part of the UN Command. At the same time, despite Stalin’s insistence that the Soviets would ‘not lift a finger’ should Kim require assistance, for which Kim would have to ask Mao, Beijing and Moscow could not resist supporting their new communist brother after Pyongyang’s initial invasion. North Korea would learn the value of having supportive acquaintances to offer material support.

As the Korean War became a cause and consequence of the then-ensuing Cold War, Mao’s deployment of the first units of the People’s Volunteer Army in October 1950 would catalyse the war’s inconclusive outcome. Had China and the Soviet Union left Kim Il Sung to fend for himself, the Korean Peninsula would now look very different. By the time the Armistice Agreement was signed – although not by South Korea – on 27 July 1953, Washington had saved Seoul.

The ink was hardly dry when, two months later, the two countries codified their relationship in a Mutual Defence Treaty. North Korea would emerge out of the war as the richer of the two Koreas. Yet, while the North would be plagued by self-enforced economic and political autarky, South Korea would undergo significant export-led industrialisation. The two Koreas would swap positions in the mid-1970s, as the South became an increasingly prosperous country.

One of the key legacies of the Korean War on South Korea remains the stationing of US troops, currently numbering approximately 28,500, in the country, which must be maintained for local and regional stability. For Pyongyang, however, the legacies of what it calls the ‘Fatherland Liberation War’ would be manifest in different ways: first, in the central roles played by deceit and mendacity within the Kim regime’s worldview, and relatedly, in the regime’s subsequent pursuit of nuclear weapons.

Pyongyang’s propaganda war began from day one. To this day, the North Korean narrative proclaims that the US and South Korea began the Korean War, as the ‘Yankee invaders’ sought to conquer Northeast Asia.

Post-ceasefire, the Kim regime added another untruth to its arsenal, namely, the notion of the US ‘hostile policy’, which continues to be invoked by the regime. The deliberately ambiguous ‘policy’ allows North Korea to decry any actions or utterances by the United States and its allies that are even remotely critical of the North Korean state or government as tantamount to a ‘policy’ that seeks regime change. This is the regime’s strategy whether it is talking about the US’ imposition of sanctions on North Korea following a missile launch; criticism of Pyongyang’s human rights violations; or condemnation of its ongoing cooperation with Moscow in Ukraine, all of which, according to the Kim regime, form part of the ‘hostile policy’.

For the Kim regime, the only response is to acquire nuclear weapons for what it deems defensive purposes. This bears more than a hint of irony, given Pyongyang’s narrative that it won the Korean War.

In contrast to Kim Il Sung’s objective behind his 1950 invasion, the North’s current ruler, Kim Jong Un, abandoned the reunification of the Korean Peninsula as a goal in January 2024. Nevertheless, while North Korea no longer views the South as part of the same, divided but indivisible Korea, the younger Kim was not willing to break completely from his grandfather’s aims. If war were to break out on the peninsula, Kim Jong Un asserted that the North would ‘occupy, subjugate, reclaim’ and ‘annex’ South Korea, and even use nuclear weapons offensively. This is a logical fallacy: you cannot re-claim something which you do not deem to be yours from the outset.

Since the Korean War, the two Koreas have diverged socially, politically, and economically. South Korea’s economy is now 50 times the size of its northern counterpart. The memories of the frozen war, however, will not disappear. Acheson’s ‘defence perimeter’ has gained renewed salience as questions of the nature of the US alliance with South Korea pervade. Relatedly, so, too, have debates over whether South Korea ought to acquire its own nuclear deterrent amid a rapidly escalating North Korean nuclear programme and mounting cooperation with Russia.

Without the United States, South Korea would certainly not have been rescued in 1953. Yet, the legacies of the inconclusive war will remain on both sides of the Demilitarized Zone. On 27 July 2025, North Korean state media warned how, one day, Pyongyang ‘will inflict a humiliating defeat on the imperial aggressors’ attempts to threaten state sovereignty’. For the hermit kingdom, the past remains the present.