World War II was a long and bloody war that lasted for six years. It officially began on 1 September 1939, when Germany invaded Poland, and lasted until both the Germans and the Japanese had surrendered to the Allies in 1945.
Estimates vary greatly about the number of lives lost during the War, but many say that the total deaths totaled roughly 62 million people; this was 2.5% of the world’s population. World War II was the most destructive conflict in history. It cost huge amounts of money, damaged property, killed millions of people, and caused more far-reaching changes than any other war ever known. Statistics confirmed that almost 1.5 million children were killed during the time of this War.
When the concentration camps throughout Europe were liberated, the world was shocked to see what horrors lay within. Around twelve million people had been murdered in total, and this number did not include those who had been used for medical experimentation. It was recorded that the Nazi doctors performed insane horrifying medical experiments on war prisoners.
Also, World War II included one of the most tragic events in the history of humanity, which is the atomic bombings of the cities of Hiroshima and Nagasaki in Japan. The first atomic bomb was dropped on the city of Hiroshima on 6 August 1945, followed by a second one on the city of Nagasaki on 9 August. Within the first two to four months of the bombings, the acute effects killed 90,000–166,000 people in Hiroshima and 60,000–80,000 in Nagasaki, with roughly half of the deaths in each city occurring on the first day. During the following months, large numbers died from the effect of burns, radiation sickness, and other injuries, compounded by illness. In both cities, most of the deceased were civilians.
Probably the most significant outcome of World War II was the destruction of the Old World Order, a process that began in WWI. The Old World Order was a political system with many power points: France, Germany, Japan, Russia, USA, etc. Each had its own interests, and mainly operated independently of one another. All were colonial powers to varying extents. The center of world political influence was Europe, varying from a specific place to another; Berlin, London, Rome and Paris all had the top spot at various times. By the end of WWII, all of this had ended. No European power has ever regained the power and prestige that several enjoyed prior to the War.
References
www.bbc.co.uk
history1900s.about.com
britannica.com