The Pity Of War: Explaining World War I is a nonfiction history book by Niall Ferguson. The central thesis of Ferguson's history book is that World War I, also called the Great War, was an atrocity and was caused almost-entirely by England. In particular, Ferguson details how Great Britain alone created the world war.

The other major theme of the book is the detailed account of the militaristic, political, social and economic events that led to World War I. Ferguson argues that the Great War was not originally a "world war," or a war that was fought by various belligerents of different nations. The war was, in fact, a continental war that began as an internal conflict in the Austro-Hungarian Empire after the assassination of Austrian Archduke Franz Ferdinand by a Bosnian revolutionary member named Gavrilo Princip. One catalyst for the continental war's escalation into a broader war are the multiple complex alliances between European countries and empires. For example, Germany and Austria-Hungary formed a defense alliance to protect each other from Russia.

Likewise, Serbia also had an alliance with Austria-Hungary. On the other end, Britain, France and Russia formed the Triple Entente to protect each other from the threat of Germany. Britain also had separate alliances exclusively with France and Russia, respectively.

The other major theme in the book is the aftermath of World War I. For instance, Ferguson examines the empires—Germany, Austria-Hungary, Ottoman Empire, and Russia—that were destroyed as part of the war's results. The victors, including Great Britain and France, benefited from the destruction of these empires, but at the cost of a weakened economy and many lives lost. The aftermath of World War I also gave the Bolsheviks an opportunity to overthrow the Czar and eventually establish the communist Soviet Union. Another momentous effect of World War I is the rise of nationalism in Germany, which would give birth to the The National Socialist German Workers' Party, also known as the Nazi Party.