, Kim Il Sung(김일성), the president of North Korea, declared war on the South. Fighting went on for three years until 1953 when an armistice was made, but to be clear, the two countries are still officially at war. This war between the Koreas was a mortifying war that not only permanently split a nation apart but was also responsible for the loss of more than 1,560,000 soldiers and civilians that are missing, captured, wounded or dead. This war used 81.6 million tons of materials, 3.55 million tons of ammunition, and in U.S. dollars alone the war cost 22.5 billion dollars. Despite the allies that aided each respected side, this war was ultimately the North Koreans against the South Koreans.
In the beginning, North Korea's biggest military sponsor was the Soviet Union as they equipped North Korea with modernized tanks, trucks, artillery, and small arms. Joseph Stalin was a huge factor in the success of the military in driving the South Korean forces all the way to Seoul within three days of invasion. With North Korea's militarist ideology and Soviet influence, their strategies were mainly offensive and they firmly believed in the saying "Offence is the best defense". Their goal and strategy was ultimately to achieve Korea's reunification by employing force, overwhelming firepower, and speed. North Korean soldiers were fiercely persistent and claimed that they would "strike back regardless of the nature of aggression, even if it is a small-scale regional guerilla war". The South Korean army was outmatched in every way possible and was incredibly weak against the North until they appealed to the United Nations for aid. North Korea, alone, suffered 290, 000 casualties and lost 90,000 men as prisoners of war by the time of the armistice in 1953. .
I keep saying the word armistice but I don't think you guys know the complete definition of the word, so I'll go ahead and clear up some confusion.