The Canadian Forces were involved in the 1950–1953 Korean War and its aftermath. 26,791 Canadians participated on the side of the United Nations (the third highest total of any non-Korean country, behind the United Kingdom who brought 56,000 men and the United States who brought 1,789,000 men), and Canada sent eight destroyers. Canadian aircraft provided transport, supply and logistics. 516 Canadians died, 312 of which were from combat. After the war, 7,000 Canadian troops remained until 1957 as military observers.

Background Japan's defeat in World War II brought an end to 35 years of Japanese colonial rule of the Korean Peninsula. The surrender of Japan to the Allied forces on 2 September 1945 led to the peninsula being divided into North and South Koreas, with the North occupied by troops from the Soviet Union, and the South, below the 38th parallel, occupied by troops from the United States.

The Soviet forces entered the Korean Peninsula on 10 August 1945, followed a few weeks later by the American forces who entered through Incheon. U.S. Army Lieutenant-General John R. Hodge formally accepted the surrender of Japanese forces south of the 38th Parallel on 9 September 1945 at the Government House in Seoul.

Although both rival factions tried initially to diplomatically reunite the divided nation, the Northern faction eventually tried to do so with military force. The North hoped that they would be able to unify the peninsula via insurgency, but the success of South Korea (Republic of Korea: ROK) in suppressing insurgency brought about the realization for the North that they would require military force. North Korea (Democratic People's Republic of Korea: DPRK) had expanded their army and Korean volunteers fighting in Manchuria in the Chinese Civil War had given their troops battle experience. The North expected to win with the war in a matter of days. Troops from North's Korean People's Army (KPA) crossed the 38th parallel on 25 June 1950 beginning a civil war.

The invasion of South Korea came as a surprise to the United Nations. The day the war began, the United Nations immediately drafted UNSC Resolution 82, which called for:

all hostilities to end and North Korea to withdraw to the 38th Parallel; a UN Commission on Korea to be formed to monitor the situation and report to the Security Council; all UN members to support the United Nations in achieving this, and refrain from providing assistance to the North Korean authorities.

When the KPA crossed into South Korea on 25 June 1950, they advanced for the capital Seoul, which fell in less than a week.

North Korea's forces continued toward the port of Pusan, a strategic goal and the seat of the ROK government. The Korean People's Army conquered all of Korea except for this tiny enclave at the end of the peninsula. The war was nearly won by the DPRK. In two days, the United States offered assistance and the United Nations Security Council asked its members to help repel the North Korean attack. Canada, the United States, Australia, United Kingdom, New Zealand, South Africa, India, the Philippines, Ethiopia, France, and other countries sent troops to Korea under a United Nations security council resolution.

Canadian Army involvement Special Force

Lieutenant-General Charles Foulkes, then Chief of the General Staff was in favour of Canada providing an infantry brigade for the 1st Commonwealth Division. Since Foulkes favoured keeping the Canadian Army's Mobile Striking Force intact for the defence of North America, he recommended recruiting a separate Special Force for the Korean War.

Recruits for the Special Force were enlisted for a period of eighteen months with recruits coming from both the Active Force, World War II veterans and adventure seeking young men. The normal recruitment standards were lowered since "the army would not wish to retain the 'soldier of fortune' type of personnel on a long term basis'". Units of the Special Force would be second battalions of the existing three Permanent Force regiments.

On 15 August 1950, the 2nd Battalion was created within Princess Patricia's Canadian Light Infantry (PPCLI) as a component of the Canadian Army Special Force in response to the North Korean invasion of South Korea. The new battalion trained in Calgary and at CFB Wainwright, before boarding on 25 November 1950, to Pusan in South Korea. The battalion landed in Korea in December and trained in the mountains for eight weeks before finally taking part in the war on 6 February, becoming a component of the 27th British Commonwealth Brigade of the IX Corps in the 8th US Army. The 2nd Battalion of the PPCLI was the first Canadian infantry unit to take part in the Korean War.

Special Force Second Battalions of the Royal Canadian Regiment and Royal 22nd Regiment were formed and sent to Korea in 1951.

By spring 1951, 8,500 Canadians troops were supporting the United Nations, alongside 12,500 British, 5,000 Filipino troops and 5,000 Turkish troops.

Area of operations

From the summer of 1951 to the end of the war, most of the Canadian involvement centered on a small area north of Seoul "between the 38th parallel on the south and the town of Chorwon on the north, and from the Sami-Chon River east to Chail-li". The Canadian war front was about across and was a section of the United Nations front occupied by British Commonwealth forces. Most of the Canadians' combat missions took place within that zone. The Canadians' two main adversaries during the war were the Korean People's Army and the Chinese People's Volunteer Army in the Battle of Kapyong. Canada's military objective was to give military support towards the resolution of the war on the central front, which was central Korea.

Operation Killer

Operation Killer was a counter-offensive by the United Nations forces to push Communist Chinese and North Korean armies back behind the Han River and recover the South Korean capital. The operation began on 21 February 1951. The 900 Canadians of the 2PPCLI set off to the front on 15 February, away. It was cold and men sat in trucks for 48 hours before arriving. They suffered frostbite and numbed limbs, and the lubricants on their weapons froze during the journey.

The Canadians arrived 17 February at 3:00pm. Their goal was to advance toward Hill 404. On their way, they were flanked on both sides but managed to continue up to the hill to have the high ground on the enemy for Operation Killer. On 21 February, the Patricias left the small village of Sangsok and headed north to their assigned objective of a new hill called Hill 419. This hill was defended by the Chinese. The Patricias D Company led by Captain J. G. Turnbull were to attack but the ridge of the hill gave an easy line of sight for the Chinese. The Canadians took fire from every direction from cannons, rockets and small arms fire. They were under intense fire. Their attack was postponed for 36 hours but they kept up aggressive patrols and eventually the Australians gained control of Hill 619. The Australians taking Hill 619 made the Chinese leave Hill 419 and the Canadians took the hill without serious opposition. From 21 to 28 February, the Patricias suffered 10 killed and more than 21 wounded. The operation ended on 6 March 1951.

The Canadians learned a strong lesson about the People's Volunteer Army during this Operation. They were told by British intelligence that there "was nothing surprising about the enemy: the concealment, mobility, poor marksmanship and stamina". The Canadians learned during the operation that the Chinese were very good at concealing automatic weapons along approach lines. Finally, the operation was successful in the objective that it had set with the United Nations forces.

Battle of Kapyong

In April 1951, Chinese forces of the 118th Division and the 60th Division attacked the Kapyong Valley in force, and pushed South Korean and New Zealand troops into retreat. Under heavy pressure, the Korean 6th Division broke, and the line collapsed. American and South Korean men poured through a gap under protective covering fire from Australians who were holding their section of the line despite heavy pressure.

The 3rd Battalion, Royal Australian Regiment (3 RAR) and 2nd Battalion, Princess Patricia's Canadian Light Infantry (2 PPCLI) were ordered to halt this Chinese advance. The mission of the men of the 27th Commonwealth Brigade was to block the two approaches to Kapyong. In only a few hours, they managed to prepare defensive positions.

On 22 April 1951 the Chinese advanced towards Kapyong Valley defeating the ROK positions in their way. The 2 PPCLI became aware of the Chinese advance from two regiments of the 6th ROK who were retreating past their positions. As one Canadian recalled it, "[W]e looked out and all we could see were South Korean troops flying past us along with all these monstrous American Vehicles they were supplied with". With this overwhelming alarm, the Canadians started digging trenches and positioning themselves on Hill 677. They also put positions on the mile-long ridge that was connected to it. Hill 677 for the Canadians was positioned on the west side of the Kapyong River. On Hill 504, dug in were the 3 RAR which was on the other side of Hill 677 and who were also ready for the Chinese attack.

The Chinese 118th Division engaged their two forward battalions on 23 April. In the early part of the battle the 1st Battalion of the Middlesex Regiment and the 16th Field Regiment of the Royal New Zealand Artillery were all but cut off. The resistance of forward positions, held by the 2 PPCLI and 3 RAR, permitted the Middlesexes to withdraw. It moved into place to provide a reserve.

The initial Chinese attack at Kapyong engaged 3 RAR on Hill 504. The Chinese then struck at the Canadian front. Waves of massed Chinese troops kept up the attack throughout the night of 23 April. After a night of fierce fighting Major Bernard O'Dowd, Officer Commanding, A Company, 3 RAR, managed to get through on a radio phone to a general of the 1st U.S. Marine Division. The general was incredulous, thinking it was an enemy agent speaking. He told O'Dowd that the unit no longer existed, that it had been wiped out the night before.

The Chinese had managed to infiltrate the brigade position by the morning of 23 April. The Australians and Canadians were facing the whole of the Chinese 118th Division and 60th Division, a force of about 20,000 men, while the 3 RAR and 2 PPCLI each had about 700 men. Throughout 24 April the battle was unrelenting. It devolved on both fronts into hand-to-hand combat with bayonet charges. The Australians, facing encirclement, were ordered to make an orderly fall back to reserve positions late in the day of 24 April and did not engage the enemy further.

2 PPCLI was completely surrounded and outnumbered by about 30 to 1. During the course of the fighting, 2 PPCLI was completely exhausted of ammunition, medical supplies, and food, and forced to defend their positions with bayonets. Captain Mills, in command of D Company, was forced to call down artillery fire on his own positions on Hill 677 several times during the early morning hours of 25 April to avoid being overrun. It had to be resupplied by air drops during this time. By dawn the Chinese attack on the Canadian position had abated, and in the afternoon of 25 April the road through to the Canadians had been cleared of Chinese, and following a Canadian offensive to clear Hill 677 on 26 April, the 2nd Battalion was relieved.

The 16th Field Regiment, Royal New Zealand Artillery, also managed to withdraw and link up with the U.S. Army's 72nd Heavy Tank Battalion. These units provided close heavy gun support during the early stages of the battle, and the RNZA provided long distance support for the 2 PPCLI during the mass attacks on the night of 25 April, targeting the overrun Canadian positions from a distance of about away.