War is defined as an active conflict that has claimed more than 1,000 lives.
Has the world ever been at peace?
Of the past 3,400 years, humans have been entirely at peace for 268 of them, or just 8 percent of recorded history.
How many people have died in war?
At least 108 million people were killed in wars in the twentieth century. Estimates for the total number killed in wars throughout all of human history range from 150 million to 1 billion. War has several other effects on population, including decreasing the birthrate by taking men away from their wives. The reduced birthrate during World War II is estimated to have caused a population deficit of more than 20 million people.
(Source: NY Times)