Interesting to me because I don't know enough about WWI.
"Think of all the horrors of the 20th Century: The Holocaust. The Bolshevik Revolution. The Cold War. Were it not for the assassination of one Austro-Hungarian archduke in 1914, none of those events would have ever happened. Historian and author Andrew Roberts explains."
https://www.youtube.com/watch?v=J9lWdkCxXYg