The first fighting began at dawn on June 25th, 1950. It is generally agreed upon that North Korea attacked first along the Ongjin Peninsula, but the South Koreans took Haeju early on in the fighting. Within an hour, North Korean heavy artillery and armored vehicles crossed the border throughout all of the 38th Parallel.
The South Koreans were extremely under-prepared, and lacked adequate anti-tank defences. By June 27th, Syngman Rhee and his top-level government officials fled Seoul in secret. Even with the bombing of a bridge over the Han River, Seoul fell on June 28th. By the end of June, only 23% of all South Korean troops could be accounted for. President Truman of the United States debated whether or not to get involved in this "civil war." He was unsure of the overall implications, of all forms of involvement. He was mostly afraid that Korea would be used by the Soviets as a diversion for US forces while the Soviets could strike a more valuable nation - or the US itself.
In addition, Korea was not part of Truman's plan for the Cold War. It laid outside of the Strategic Defense Perimeter. However, Korea's proximity to Japan, an American protectorate, caused Truman to act. He proposed an invasion of Korea to the UN. The UN approved the invasion, and by July, US/UN troops were in Korea.
July 6th, 1950 marked the first US battle in Korea. US forces attempted to delay Communist forces at Osan, but failed under North Korean tanks. Later, in the Battle of Taejon, American forces were again repelled from the city by North Korean forces. In August, American, UN and South Korean troops had been pushed back into the area around Pusan. In September, the "Pusan Perimeter," a line defined by the Nakdong River, had been secured. It controlled about 10% of South Korea - the rest was under control of the Communist North.
At this time, the North Koreans, battered by weeks of non-stop combat and exhaustion, are severely outnumbered and outgunned. Owing to their extremely long and thin supply lines, being constantly bombed by US Air Force, they are also lacking supplies. But in the initial stages of the battle, they still held the initiative.
In contrast, the United Nations forces outnumbered the North Korean forces in the perimeter by 170,000 to 90,000 men. They also have undisputed control of the seas of Korea as well as nearly unimpeded air superiority over the skies of the peninsula.
The Battle of the Pusan Perimeter raged throughout August and September, and during this time, the US Air Force consistently bombarded enemy lines, roads and bridges. The North Koreans had to hide during day and only conduct operations at night. General Douglas MacArthur, the UN Commander-in-Chief, planned a breakout from the Perimeter at Pusan by using an amphibious assault and landing at Inchon, a city in South Korea that was occupied by the North.
More than 60,000 men, mostly American servicemen from Japan with South Korean and few UN multinational units attached to it, were landed at Inchon in mid-September under heavy cover from the Allied artillery. The men landed with great success, and met light resistance from North Koreans who were occupied at Pusan.
At the same time, the troops stuck in Pusan began an assault on Communist forces, who were poorly instructed and led as to where to go. Kim Il-Sung didn't follow the advice of Mao's General Zhou Enlai, or Stalin's General Matvei Zakharov, and defended Pusan instead of falling back to defend Seoul. Seoul was recaptured by UN forces on September 25, 1950. Following the recapture of Seoul, MacArthur pursued the idea to invade the North Korean homeland. At first, President Truman was opposed to the idea, but
MacArthur was eventually granted permission by Truman's Secretary of Defense.
When the Democratic People's Republic of Korea refused unconditional surrender to the UN forces, MacArthur's forces crossed back over the 38th Parallel on 1 October 1950. As their capital city Pyongyang fell to South Korean and American forces on 19 October, the North Korean government moved their capital to Sinuiju, and when the UN forces approached it, they moved it again to Kangyye in north-central North Korea. By the end of the month, 135,000 North Korean POWs were held by the UN forces. The People's Republic of China had been mobilizing for an invasion of Taiwan and the Republic of China when news of the UN forces crossing the 38th Parallel reached Chairman Mao Zedong and Premier Zhou Enlai. Even though there was demobilization of the Chinese army taking place since the end of the civil war in 1949, Mao and the Chinese government, not wanting to postpone their invasion of Taiwan despite being blocked by US 7th Fleet sailing across Taiwan Strait, and after much debate, reordered the mobilization. Thus done, it put the already demobilized units of the People's Liberation Army, the armed forces of China, back into active service, and sent them to the Sino-Korean border.
As early as August 1950, the Chinese government have already warned of possible intervention in the war at the time UN forces crossed the 38th Parallel. However, President Truman dismissed the warning, stating that "it was rather a bald attempt to blackmail the UN."
Before China's entry to the war, Mao sent Zhou Enlai and a Chinese delegation to Moscow on 8 October and arriving two days later to secure support from Stalin. As soon as support was secured, Communist Chinese troops crossed into North Korea of October 19. They began the First Phase Offensive on October 25, 1950. Backed by Soviet air-support, the Chinese won a few battles using guerrilla tactics such as night attacks and hit-and-run assaults. But, owing to their yet-few numbers (they are outnumbered 450,000 to 200,000) and lack of supplies, they abandoned their offensive, having inflicted defeats on the UN and US for the first time. Their success made the Chinese command confident of the abilities of their forces.
General Douglas MacArthur was confident of the intelligence brought by the CIA that the Chinese forces in Korea were only 50,000 men strong. However, unknown to him and the rest of the UN Command was that the Chinese have already amassed more than 1,000,000 men near the Sino-Korean border, not including the 240,000 Chinese already in North Korea early November. The Chinese forces used excessive camouflage and deception to deceive and fool the US intelligence. So MacArthur ordered the all-out "Home by Christmas Offensive" in November 24, confident that American forces are to win the war before Christmas of 1950.
Chinese forces overrun UN positions during the Battle of the Cheongcheon River.
As the UN forces advanced, a dangerous gap developed between units in the western and eastern fronts. Unknown to the UN forces, however, the Chinese are already waiting in ambush. On November 25, the Chinese counter-attacked the UN "Home by Christmas Offensive" with their Second Phase Offensive, the largest offensive operation of the war with more than 1,000,000 Chinese servicemen, nearly all of them infantrymen, taking part. The Chinese Air Force is to participate in the war for the first time.
At the Battle of the Cheongcheon River on the western front in late November to early December, 580,000 Chinese clashed with 353,000 US, South Korean, Turkish and British Commonwealth troops of the US 8th Army, making it the largest battle of the war. After overrunning the ROK II Corps and decimating the US 2nd Infantry Division, and despite the heroic hold-out defense by the Turkish Brigade near Kunu-ri, the Chinese went on encircling and destroying the rest of the US 8th Army. The British 27th Commonwealth Brigade, badly mauled from the battle, was the only unit to make it out of the battle area; the rest were completely routed and destroyed. The US 8th Army command was no more, its commander, General Walton Walker, and many of his staff being killed by shrapnels and artillery shells during the battle.
Meanwhile, at the eastern front, theBattle of Chosin Reservoirtook place almost the same time as was in Cheongcheon River. However, the 30,000-strong US IX Corps fared better than its parent army, the US 8th Army. Though unprepared for the Chinese' 3-pronged assault, they successfully evacuated from the area under the US Air Force cover, albeit with some 15,000 collective casualties.
British prisoners of the 27th Commonwealth brigade in Pyongyang.
With most of the US 8th Army gone, and with the Chinese forces retaking much of northern and western North Korea including its capital Pyongyang, which for a time was staunchly defended by British, Greek and Filipino UN forces but later surrendered after much losses, the rest of the UN forces staged a mass evacuation at the port of Heungnam in west-central North Korea in 24 December. By Christmas 1950, Chinese forces, though having suffered 36% loss of their overall strength during the recent offensive, are already in the immediate north of the 38th Parallel. It was at this time the North Korean People's Army was rebuilt, after being nearly destroyed by successive UN offensives earlier during the war; it was now under Chinese command, since Kim Il-Sung was deprived of command by the former in 17 December. The UN issued a ceasefire to the Chinese government, but was rejected by the latter.
end of the month, 135,000 North Korean POWs were held by the UN forces. On 31 December 1950, as Communist forces once again poured across the 38th Parallel, the Third Phase Offensive began. This offensive used a tactic of night-time encirclement which the help of the element of surprise and their bloodily reduced yet still numerically superior forces, with the newly-rebuilt North Korean People's Army in assistance. On 4 January, Seoul fell for a second time. At this time, MacArthur first considered using an atomic bomb.
On 17 February 1951, 16 days after the UN General Assembly condemned China as the aggressor, the Communist forces implemented the Fourth Phase Offensive. It drove the Communist forces further south, linking up with local communist guerrillas in the mountains of South Korea.
By this time, UN forces, now severely reduced, are in constant retreat. As time went on, MacArthur became even more obsessed with using the atomic bomb. General MacArthur, who was widely popular among his men in Korea, felt that he was under the UN command, with US support. He was, in fact, declared as the Supreme Commander of the UN Forces. Therefore, MacArthur largely felt he had a good deal of autonomy from the US government.
MacArthur viewed the Korean War as a war on China and North Korea, whereas Truman viewed the war as only a war on Korea. MacArthur had already wanted to invade China prior to the Chinese invasion of Korea in October of 1950. For Truman, any such move could escalate into another world war.
President Harry Truman decided on 11 April 1951, that Supreme Commander Douglas MacArthur, was to be relieved from command of the American, South Korean and UN Forces in Korea. The largest factors included MacArthur's idea of using an atomic bomb, which he considered at his command.
In fact, Truman had stated, "The military commander in the field will have charge of the use of the [atomic] weapons, as he always has." The real reason, as many historians and contemporaries believe, is that Truman felt he would lose in the polls if he was perceived as being commanded by MacArthur.
In Asia, MacArthur was met by Emperor Hirohito, the first time an Emperor of Japan had visited a foreigner without a title or rank. He returned to San Francisco to a throng of 500,000 people, who eagerly watched a parade in his honor.
On 19 April 1951, at the invitation of Congress, MacArthur gave a notable speech to a joint-session of Congress. In the speech, he declared boldly, "Once war is forced upon us, there is no other alternative than to apply every available means to bring it to a swift end. War's very object is victory, not prolonged indecision. In war there can be no substitute for victory. Pressured by MacArthur's speech, the Joint Chiefs of Staff convinced Truman to agree with the decision of bombing China with nuclear weapons. Truman reluctantly agreed to detonate an atomic bomb in China. It was scheduled in 24 April 1951. However, the Chinese and North Koreans have already launched their all-out offensive on 22 April, which will prove to be the last in the war, dubbed as the Fifth Phase Offensive.
But the atomic bombing took place nonetheless. Loaded in a B-29 Superfortress bomber from Okinawa, it made its target on Shenyang, China on 24 April. It caused the deaths of 300,000 people in the city, much more deadlier than Hiroshima or Nagasaki. However, instead of cutting of China from North Korea, This unified all of china against the US forces. Days after the bombing, the resolve of the Chinese stiffened even further, and all of China undoubtedly rallied in support of Mao and the government, sparking a civil war in Taiwan. At the capital city of Beijing, more than 5,000,000 people rallied, carrying images of Mao and the flags of China and the hammer-and-sickle symbol of communism, and shouting "Death to the imperialists! Glory to China, Communism, and Chairman Mao!" throughout the months of April and May 1951. Elsewhere, all over the country &the Soviet Union, similar rallies and chants took place. Meanwhile, the Soviet leader, Joseph Stalin, have been contemplating of an invasion of Japan and NATO states in retaliation of the atomic bombing of his ally. The American government now has a dilemma: whether the United States has to enter into another world war or not after only almost 6 years of respite. There was an emergency meeting in the U.S. Congress, and most could not agree over another world war. Despite the atomic bombing of Shenyang, which nearly caused another world war, the Congress and the Joint Chiefs of Staff agreed on a ceasefire The offensive went on, and by 18 May 1951, the UN forces were once again desperately fighting on the perimeter of Pusan. On 28 May, the scope of the war somewhat expanded. With the US 7th Fleet reassigned from the Taiwan Strait to near Pusan to assist for the defense of the perimeter, the Chinese finally staged their assault on Taiwan, completing the campaign on 10 June and capturing the Nationalist leader Chiang Kai-Shek. At the same time Taiwan was invaded, the US-occupied island of Okinawa was not spared from the Chinese assault, and was done at 13 June. For a time, with these events, it seemed that a next world war was at hand. Despite weeks of harsh resistance and near-endless naval and aerial assistance, the Second Pusan Perimeter collapsed on 12 July, with the South Korean leader Syngman Rhee and the new UNC Commander-in-Chief Matthew Ridgway along with the rest of the UNC staff and thousands of UN staff captured by the Communists. With the entire Korean peninsula now under Communist hands, there were no other motivations for further military ventures in the name of the United Nations in Korea. An emergency meeting at the United Nations General Assembly was held in 13 July 1951, and a referendum was held over the continuation over the war. Most nations, with the exception of the United States, Great Britain and France, voted "no". The United Nations Command was thus officially disbanded.
Peace talks took place between two sides, the United States and South Korean on one side and North Korea, China and the Soviet Union on the other. The talks were initially held in 20 July at Masan in southeastern Korea, but was later held at Seoul in 23 June. This was the Korean Armistice Agreement. The talks occurred almost non-stop, with Japan joining on 25 June in the side of the UN. An agreement was reached by the belligerents in 27 July, effectively ending the war. The aftermath.. is not so great for the US & Nato, The invincibility of the US shattered by a nation it's size thus shattered the faith in the US government, Sparking a communist civil war in the US, Indochina falls under communism as France loses without US Support so the 1954 Geneva conference never happens. For China & the reds, This would be an absolute win as people throughout the Soviet & Chinese states celebrate, averting the Sino Soviet Split & Giving the soviets a massive boost to aid Egypt in the eventual Suez Crisis against Brtian & France.