It can be argued that WWII never really ended or that the cold war wasn’t really all that cold. Immediately after WWII, in fact technically still during the War in the Pacific,Indonesia declared it’s independence triggering an armed conflict with the Dutch and British.
Under pressure from radical and politicised pemuda (‘youth’) groups, Sukarno and Hatta proclaimed Indonesian independence, on 17 August 1945, two days after the Japanese Emperor’s surrender in the Pacific. The following day, the Central Indonesian National Committee (KNIP) elected Sukarno as President, and Hatta as Vice-President. It lasted until 1949.
War in Vietnam (September 13, 1945 – March 30, 1946)
The War in Vietnam, codenamed Operation Masterdomb, was a post–World War II armed conflict involving a largely British-Indian and French task force and Japanese troops from the Southern Expeditionary Army Group, versus the Vietnamese communist movement, the Viet Minh, for control of the country, after the unconditional Japanese surrender.
The Korean War
On June 25, 1950, the Korean War began when some 75,000 soldiers from the North Korean People’s Army poured across the 38th parallel, the boundary between the Soviet-backed Democratic People’s Republic of Korea to the north and the pro-Western Republic of Korea to the south. This invasion was the first military action of the Cold War. By July, American troops had entered the war on South Korea’s behalf. As far as American officials were concerned, it was a war against the forces of international communism itself.
In July 1951, President Truman and his new military commanders started peace talks at Panmunjom. Still, the fighting continued along the 38th parallel as negotiations stalled. Both sides were willing to accept a ceasefire that maintained the 38th parallel boundary, but they could not agree on whether prisoners of war should be forcibly “repatriated.” (The Chinese and the North Koreans said yes; the United States said no.) Finally, after more than two years of negotiations, the adversaries signed an armistice on July 27, 1953. The agreement allowed the POWs to stay where they liked; drew a new boundary near the 38th parallel that gave South Korea an extra 1,500 square miles of territory; and created a 2-mile-wide “demilitarized zone” that still exists today.
The Indochina war.(19 December 1946 – 1 August 1954.)
The Indochina War (also known as the First Indochina War in) began in French Indochina(Vietnam) on 19 December, 1946, and lasted until 1 August, 1954. Fighting between French forces and their Viet Minh opponents in the south dated from September 1945. The conflict pitted a range of forces, including the French Union’s French Far East Expeditionary Corps, led by France and supported by Emperor Bảo Đại’s Vietnamese National Army against the Viet Minh, led by Ho Chi Minh and the People’s Army of Vietnam led by Vo Nguyen Giap. Most of the fighting took place in Tonkin in northern Vietnam, although the conflict engulfed the entire country and also extended to French Indochina protectorates of Laos and Cambodia.
Greek Civil War(30 March 1946 – 16 October 1949)
The first major military conflict of the Cold War. Communist rebels supported by Yugoslavia and other Communist nations fought against the pro-Western government of Greece, which was given significant support by the United States and Great Britain. The war ended with a government victory.
The Vietnam War (1 November 1955 – 30 April 1975)
The Vietnam War was a long, costly and divisive conflict that pitted the communist government of North Vietnam against South Vietnam and its principal ally, the United States. The conflict was intensified by the ongoing Cold War between the United States and the Soviet Union. More than 3 million people (including over 58,000 Americans) were killed in the Vietnam War, and more than half of the dead were Vietnamese civilians. Opposition to the war in the United States bitterly divided Americans, even after President Richard Nixon ordered the withdrawal of U.S. forces in 1973. Communist forces ended the war by seizing control of South Vietnam in 1975, and the country was unified as the Socialist Republic of Vietnam the following year.
Suez Crisis (29 October 1956 – 7 November 1956)
On 29 October, Israel invaded the Egyptian Sinai. Britain and France issued a joint ultimatum to cease fire, which was ignored. On 5 November, Britain and France landed paratroopers along the Suez Canal. The Egyptian forces were defeated, but they did block the canal to all shipping. It later became clear that the Israeli invasion and the subsequent Anglo-French attack had been planned beforehand by the three countries.
Congo Crisis (5 July 1960 – 25 November 1965)
The Congo Crisis was a period of political upheaval and conflict in the Republic of the Congo (today the Democratic Republic of the Congo) between 1960 and 1965. It began almost immediately after the Congo became independent from Belgium and ended, unofficially, with the entire country under the rule of Joseph-Désiré Mobutu. Constituting a series of civil wars, the Congo Crisis was also a proxy conflict in the Cold War, in which the Soviet Union and United States supported opposing factions. Around 100,000 people are believed to have been killed during the crisis.
Yom Kippur War (October 6–25, 1973)
The Yom Kippur War, Ramadan War,also known as the 1973 Arab–Israeli War, was a war fought by a coalition of Arab states led by Egypt and Syria against Israel from October 6 to 25, 1973. The fighting mostly took place in the Sinai and the Golan Heights, territories that had been occupied by Israel since the Six-Day War of 1967. Egyptian President Anwar Sadat wanted also to reopen the Suez Canal. Neither specifically planned to destroy Israel, although the Israeli leaders could not be sure of that.
Soviet–Afghan War (December 24, 1979 – February 15, 1989)
The Soviet–Afghan War lasted over nine years, from December 1979 to February 1989. Insurgent groups known as the mujahideen fought against the Soviet Army and the Democratic Republic of Afghanistan. Between 562,000 and 2,000,000 civilians were killed and millions of Afghans fled the country as refugees,mostly to Pakistan and Iran.
The USSR entered neighboring Afghanistan in 1979, attempting to shore up the newly-established pro-Soviet regime in Kabul. In short order, nearly 100,000 Soviet soldiers took control of major cities and highways.
Foreign support propped up the diverse group of rebels, pouring in from Iran, Pakistan, China, and the United States.
Falklands War (Apr 2, 1982 – Jun 14, 1982)
Falkland Islands War, also called Falklands War, Malvinas War, or South Atlantic War, a brief undeclared war fought between Argentina and Great Britain in 1982 over control of the Falkland Islands (Islas Malvinas) and associated island dependencies.
It began on Friday, 2 April 1982, when Argentina invaded and occupied the Falkland Islands in an attempt to establish the sovereignty it had claimed over them. On 5 April, the British government dispatched a naval task force to engage the Argentine Navy and Air Force before making an amphibious assault on the islands. The conflict lasted 74 days and ended with the Argentine surrender on 14 June 1982.
The Yugoslav Wars/Balkan Wars (31 March 1991 – 11 June 1999)
The Yugoslav Wars were a series of ethnically-based wars and insurgencies fought from 1991 to 1999 in the former Yugoslavia. These wars accompanied and facilitated the breakup of the Yugoslav state, when its constituent republics declared independence, but the issues of ethnic minorities in the new countries (chiefly Serbs, Croats and Albanians) were still unresolved at the time the republics were recognized internationally. The wars are generally considered to be a series of separate but related military conflicts which occurred in, and affected, most of the former Yugoslav republics.
The conflicts in Croatia and Bosnia claimed more than 120,000 lives. In Bosnia alone more than half of those in the pre-war population were forced out of their homes, either in campaigns of ethnic cleansing or bids to find safety.
Bosnia’s capital Sarajevo was under siege for 44 months, during which its 350,000 residents struggled to get basic necessities. At least 10,000 were killed by sniping and shelling from Serbs in the surrounding mountains.
Thousands of people were held in camps on all three sides, where many were tortured, starved or executed. It is estimated that more than 20,000 women, mostly Muslims, were systematically raped.
The worst atrocity occurred in July 1995 when Bosnian Serb forces overran the eastern town of Srebrenica, slaughtering almost 8,000 Muslim men and boys in a massacre described by two international courts as genocide.
I am limiting the wars to the last decades of the 20th century, although the Cold War ended with the fall of communism in the East bloc, the tensions that caused that conflicts never really ended and are currently flaring up again.
I left out the 1st Gulf war because that is basically still an unresolved issue and is still ongoing.
The 21st century has seen a great number of wars, some of them which are still ongoing. The current “World war” is the Global war on terror.