attacked the Kapyong valley and forced South Korean and Australian troops into retreat; other UN troops, including the Australian, were ordered to halt the attack. After a night of fierce fighting, during which the allied positions were overrun, the Australians counterattacked and recaptured their positions, stalling the Chinese advance. The Australians suffered very few casualties. For their contribution to this action, 3 RAR (Royal Australian Regiment) was awarded a U.S. Presidential Citation. Australian soldiers also participated in Operation Commando, an attack against a Chinese-held position in a bend of the Imjin River, a river running north–south that crosses the 38th parallel north just above Seoul. The attack began on October 3, 1951, and after five days of heavy fighting the Chinese withdrew. Twenty Australians were killed in the battle and 89 were wounded. As the war continued, several other nations grew less willing to contribute more ground troops. Australia, however, increased its troop strength in Korea. 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. Canada's participation included a brigade of troops, eight naval vessels, and 22 pilots for U.S. jet squadrons. The first Canadian aid to the UN forces came from the Royal Canadian Navy. On July 12, 1950, three Canadian destroyers, HMCS Cayuga, HMCS Athabaskan and , were sent to Korea to serve under United Nations Command. These ships supported the assault at Inchon and played an especially important role in the evacuation. Canadian ships also kept up the blockade on North Korean waters and protected coastal villages from attack. The Canadian army also helped UN forces repulse and defend major positions from Chinese attack. 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. The Canadian military was revitalized as a result of the Korean War. A changeover to U.S.-designed weapons and equipment