Started with the assassination of Archduke Franz Ferdinand of Austria.
More than 15 million people died while fighting.
Involved 32 countries.
It was the most widespread war in history, and directly involved more than 100 million people from over 30 countries.
The first war to use nuclear weapons.
It was the most deadly war in human history. Over 60 million people were killed.
The cold war was a time of military tension after World War II between the Soviet Union and the USA. It was not like a traditional war and no official shots were fired, rather it was a war of espionage between the two countries and their allies. However it is believed that a number of special agents from both countries were killed.
The Korean war was between North Korea and South Korea. More than 2 million Koreans died, most of them being from the north.
North Korea was led by communist leader Kim Il-Sung, and was helped mainly by China and the USSR.
South Korea was aided by countries in the United Nations, especially the U.S.
The Vietnam war started out as a war between North and South Vietnam. North Vietnam was fighting for a communism and the South Vietnamese were fighting to keep democracy in the nation.
Russia, China and their allies joined North Vietnam and the U.S, Australia and their allies joined South Vietnam.
North Vietnam won the war in the end and the two halves of the country were reunited in 1976.
The Cuban Missile Crisis occurred when the Soviet Union began building missile sites in Cuba in 1962. The U.S. were worried that the Soviet Union would attack them from Cuba and blocked all trade. There was very high tension between the two counties at that time and it is said to be the closest the world came to nuclear war during the entire span of the cold war.
An insurgent group called the mujahideen fought against the USSR presence in the country and the Afghan Government.
Between 850,000–2 million civilians were killed during the course of the war and millions of Afghans left the country as refugees.
The war is considered part of the cold war.
35 nations waged war on Iraq for invading Kuwait. The fighting was led by the U.S.A. The army was made of of 670,000 troops from 28 countries. 425,000 of those troops were from the United States.
The Afghanistan war started when U.S troops invaded Afghanistan with the aid of the U.K. Later all NATO countries joined.
The point of the war was to dismantle al-Qaeda and to deny it's operations in Afghanistan by removing the Taliban from power.
The Iraq war was a conflict between the U.S and the Iraq government. It started with the invasion of Iraq by a coalition of nations led by the the U.S. The point of the invasion was to take down the Iraqi leader Saddam Hussein.