World War II is the story of the 20th Century. The war officially lasted from 1939 until 1945, but the causes of the conflict and its horrible aftermath reverberated for decades in either direction. While feats of bravery and technological breakthroughs still inspire awe today, the majority of the war was dominated by unimaginable misery and destruction. In the late 1930s, the world's population was approximately 2 billion. In less than a decade, the war between the nations of the Axis Powers and the Allies resulted in some 80 million deaths -- killing off about 4 percent of the whole...