Behind the scenes of war

The 20th century was the bloodiest age in all of world history. During this era, for the first time, humanity was introduced to the concept of a "world war." Taken together, World Wars I and II resulted in a total of 65 million people losing their lives. About half of these casualties were civilians who had nothing to do with these wars. Children, defenseless women and the elderly alike were massacred cruelly. So, one might ask, how did the world find itself in the midst of such colossal insanity?