The aftermath of the Korean War set the tone for Cold War tension between superpowers. The Korean War was important in the development of the Cold War, as it showed that the two superpowers, United States and Soviet Union, could fight a "limited war" in a third country. The "limited war" or "proxy war" strategy was a feature of conflicts such as the Vietnam War and the Soviet War in Afghanistan, as well as wars in Angola, Greece, and the Middle East.

In the aftermath of the war, the United States funneled significant aid to South Korea under the auspices of the United Nations Korean Reconstruction Agency. Concomitantly, North Korean reconstruction was assisted by "fraternal socialist nations:" the Soviet Union and China. In the years immediately following the war, North Korea's growth rate of total industrial output exceeded South Korea's and averaged 39% between 1953 and 1960.

Background The Korean War was the first war in which the United Nations (UN) participated outside the Western world. The UN Command in South Korea is still functional.

Around June 1950, the Korean War became an international crisis, as it made communist and capitalist countries around the world go against each other. By the end of World War II, the Soviet Union sought to spread communism to other nations and did so by providing political, logistical, and diplomatic support and assisted in the plans to invade South Korea. The Soviets provided military training for North Korean and Chinese troops.

In response, the United States, fearing that the Soviets would control and spread communism to the entire Korean Peninsula and South Pacific, sent troops into South Korea to support its military forces. Those actions quickly escalated into other countries. The UN supported the south, and China supported the north. Both sides got involved in the conflict. Kim Il Sung’s invasion solved a number of critical problems for the Truman administration, and did wonders in building the American Cold War position on a world scale.

The war devastated both North and South Korea. Both suffered major damage to their economies and infrastructure, as a result of bombings, artillery strikes and loss of life, including military personnel and civilians.

North Korea As a result of the war, "North Korea had been virtually destroyed as an industrial society". After the armistice, Kim Il Sung requested Soviet economic and industrial assistance. In September 1953, the Soviet government agreed to "cancel or postpone repayment for all ... outstanding debts", and promised to grant North Korea one billion rubles in monetary aid, industrial equipment and consumer goods. Eastern European members of the Soviet Bloc also contributed with "logistical support, technical aid, [and] medical supplies". China canceled North Korea's war debts, provided 800 million yuan, promised trade cooperation and sent in thousands of troops to rebuild damaged infrastructure. Contemporary North Korea remains underdevelopedNorth Korea cornered with snowballing debts-The Korea Herald. View.koreaherald.com (18 August 2010). Retrieved on 12 July 2013. and continues to be a totalitarian dictatorship since the end of the war, with an elaborate cult of personality around the Kim dynasty.

The means of production are owned by the state through state-run enterprises and collectivized farms. Most services—such as healthcare, education, housing and food production—are subsidized or state-funded. Estimates based on the most recent North Korean census suggest that 240,000 to 420,000 people died as a result of the 1990s North Korean famine and that there were 600,000 to 850,000 unnatural deaths in North Korea from 1993 to 2008. A study by South Korean anthropologists of North Korean children who had defected to China found that 18-year-old males were shorter than South Koreans their age because of malnutrition.

Present-day North Korea has the highest number of military and paramilitary personnel in the world, with 7,769,000 active, reserve and paramilitary personnel, or approximately of its population. Its active-duty army of 1.28 million is the fourth largest in the world, after China, the United States and India; consisting of of its population. North Korea possesses nuclear weapons.

A 2014 UN inquiry into abuses of human rights in North Korea concluded that, "the gravity, scale and nature of these violations reveal a state that does not have any parallel in the contemporary world," with Amnesty International and Human Rights Watch holding similar views.

South Korea South Korea, which started from a far lower industrial base than North Korea (the latter contained 80% of Korea's heavy industry in 1945), stagnated in the first postwar decade. In 1953, South Korea and the United States signed a Mutual Defense Treaty. In 1960, the April Revolution occurred and students joined an anti-Syngman Rhee demonstration; 142 were killed by police; in consequence, Syngman Rhee resigned and left for exile in the United States. Park Chung Hee's May 16 coup enabled social stability. From 1965 to 1973, South Korea dispatched troops to South Vietnam and received $235,560,000 in allowance and military procurement from the United States. The gross national product increased fivefold during the Vietnam War. South Korea had one of the world's fastest-growing economies from the early 1960s to the mid-1990s.

South Korean anti-Americanism after the war was fueled by the presence and behavior of United States Forces Korea military personnel and U.S. support for Park's authoritarian regime, a fact still evident during the country's democratic transition in the 1980s.Kristof, Nicholas D. (12 July 1987). "Anti-Americanism Grows in South Korea". The New York Times. However, anti-Americanism has declined significantly in South Korea in recent years, from 46% favorable in 2003 to 74% favorable in 2011,"Global Unease With Major World Powers" . Pew Research Center. 27 June 2007. making South Korea one of the most pro-U.S. countries in the world.Views of US Continue to Improve in 2011 BBC Country Rating Poll , 7 March 2011.

A large number of mixed-race "GI babies" (offspring of U.S. and other UN soldiers and Korean women) were filling up the country's orphanages. Because Korean traditional society places significant weight on paternal family ties, bloodlines, and purity of race, children of mixed race or those without fathers are not easily accepted in South Korean society. International adoption of Korean children began in 1954.Jang, Jae-il (11 December 1998). "Adult Korean Adoptees in Search of Roots". The Korea Times. The U.S. Immigration Act of 1952 legalized the naturalization of non-Blacks and non-Whites as U.S. citizens and made possible the entry of military spouses and children from South Korea. With the passage of the Immigration Act of 1965, which substantially changed U.S. immigration policy toward non-Europeans, Koreans became one of the fastest-growing Asian groups in the United States.Choe, Yong-Ho; Kim, Ilpyong J.; Han, Moo-Young (2005). "Annotated Chronology of the Korean Immigration to the United States: 1882 to 1952".

Other involved nations

Australia

From 1950 to 1953, 17,000 Australians fought as part of the United Nations multinational forces. As the war continued, several other nations grew less willing to contribute more ground troops. Australia, however, increased its troop strength in Korea."Korean War 1950–53" . Australian War Memorial

After the war ended, Australians remained in Korea for four years as military observers. Australia gained political and security benefits, the most significant being the signing of the ANZUS Treaty with the United States and New Zealand.

Canada

Canada sent 29,791 troops to the war, with 7,000 more remaining to supervise the ceasefire until the end of 1955. Of these 1,558 became casualties, including 516 deaths, most of them through combat."Canadians in Korea, 1950–1953" . Korean-War.com, accessed 23 June 2006.

The Canadian military was revitalized as a result of the Korean War. A changeover to U.S.-designed weapons and equipment had been planned for the 1950s, but the emergency in Korea forced the use of war stocks of British-designed weapons from World War II. In the late 1950s, Canada adopted a variety of weapons.

The Korean War was the last major conflict Canadian forces participated in until the 1991 Persian Gulf War, and the last major combat by ground troops until 2002 in Afghanistan. Canada played a minor role in the fighting in Cyprus in 1974 and in the Balkans at Medak Pocket in the 1990s.

France At a time of political difficulties due to lack of cabinet members and a prime minister, the French government eventually provided military support to South Korea by sending over the French Army's bataillon français De l'ONU of over 3,000 soldiers and sailors. This battalion played a significant role in defending the 38th parallel on the Korean Peninsula and the South Korean Capitol City Seoul between 1950 and 1954. The French at the time were worried that if they failed in their efforts it would harm future relations between them, Indochina and the UN.

India During this time India was newly independent from British rule and viewed the Korean conflict as a motivation and also a threat. During the Cold War New Delhi became more concerned of India's well-being because of the spread of communism and the constant support of the USSR and China to North Korea. These events could lead to communist influence getting to India. India supported the UN Security Council in the avocation of the power of unity among the major powers to work together towards a solution of the conflict.

Japan As American occupation armies were dispatched to the Korean peninsula, Japan's security became problematic. Under United States guidance, Japan established Reserved Police, later the Japan Self-Defense Forces (自衛隊). The signing of the Treaty of Peace with Japan (日本国との平和条約; popularly known as the Treaty of San Francisco) was also hastened to return Japan back into international communities. In the eyes of some American policy makers, the non-belligerency clause in the Constitution was already being considered a "mistake" by 1953.

Economically, Japan was able to benefit vastly from the war, and the Korean War greatly helped the rise of Japan's economy and its development into a world power. American requirements for supplies were organized through a Special Procurements system, which allowed for local purchases without the complex Pentagon procurement system. Over $3.5 billion was spent on Japanese companies, peaking at $809 million in 1953, and the zaibatsu went from being distrusted to being encouraged. Among those who thrived not only on orders from the military but also through American industrial experts, including W. Edwards Deming were Mitsui, Mitsubishi, and Sumitomo. Japanese manufacturing grew by 50% between March 1950 and 1951, and by 1952, pre-war standards of living were reached and output was twice the level of 1949. Becoming an independent country after the Treaty of San Francisco saved Japan from the burden of expense of the occupation forces.

During the war, 200,000 to 400,000 Koreans fled to Japan relying on relatives already living in Japan to provide them with shelters and necessary paperwork to live legally. They joined with those having fled from Jeju and formed the largest post-World War II Korean population group in Japan. While they initially had no strong political alignment, they were eventually split into factions supporting either North or South Korea with few holding on to the ideal of unified Korea.

People's Republic of China