"Peace cannot be kept by force. It can only be achieved by understanding. Our longing for understanding is eternal." Einstein.
Some people believe that war is necessary in order to stop injustice. The belief that some wars are worth fighting is called "Just War Theory."People who are against war are often called pacifists. "Pacifism" is the refusal to kill. "Pacifism" is a philosophy made popular by Mahatma Ghandi, who successfully practiced nonviolent resistance in his country's struggle to free itself from British rule.World War I (1914-1918) was known as "the war to end all wars," because people believed that there would be no more wars when it was over. It was the first war which included the use of chemical weapons, the bombing of civilians and genocide. Over 9 million soldiers died during the war and almost as many civilians.During World War II (1939-1945), 50 million people were killed, which includes soldiers and civilians from all the countries involved. The population of the entire planet at the time was around 2.1 billion.The United States is the only country to have used a weapon of mass destruction against another country. On August 6, 1945, during World War II, the United States dropped an atomic bomb on Hiroshima, Japan. About 92,000 people were killed that day. At least twice that number died later of radiation and other effects of the bomb. Three days later, on August 9th, another atomic bomb was dropped on Nagasaki, Japan.Not all countries go to war: for example, Switzerland remained neutral during World War I and World War II. Soldiers who refuse to participate in wars they find morally wrong are called "conscientious objectors. (less info)