nothing it was a good war but it was bad and it was lost by both sides
The Great War was incredibly significant in terms of men and materials lost, in the downfall of empires, and most importantly in the setting up of World War II. With over 10 million dead after the war, England and France, in particular, lost an entire generation of men who would fill leadership positions. The sons of the rich and powerful went to war and with so many dead, there was nobody to fill leadership roles throughout the 1920s and 30s. The same mentality that started WWI was still around, and that helped cause WWII. Empires such as the Ottoman Empire ended, leaving a huge vacuum of power in the Middle East which the British filled. The problems they stirred up in Palestine and other areas are still with us even today! Most significantly, though, was the terrible Treaty of Versailles that ended the war. Germany was forced to make war payments and reparations that they never could make. The awful conditions in that country after the war led to the rise of the National Socialist party under Hitler. We tend to forget that WWI even happened yet it was a major cause of WWII and the setting up of the world as we know it today. WWI was the very first total war, meaning that everyone was involved. At the home front, civilians were being attacked for the first time in any war. WWI also led to the ratification of the 19th amendment which gave women the right to vote. The war also led to women having a more important role in society and gave women jobs they normally wouldn't have.
The Bolshevik Revolution in Russia towards the end of the war led to 'Red scares' and encouraged conspiracy theories and anticommunist movements like Fascism. World War 1 left Europe and some other parts of the world disorientated and unsettled.
Modern historians consider World War One to be the seed that caused virtually all major conflict in the 20th century. That is, if you look at any conflict post-1918, you can relatively easily trace back causes to something that happened as a direct result of World War One.
Here's a short list of immediate effects that WW1 had:
- Creation of the USSR. - the Communist takeover of the Russian Empire would never have occurred without WW1. Indeed, the most likely path that the Russian Empire was on would have resulted in it becoming a Constitutional Monarchy much like Britain, were it not for WW1.
- The Great Depression - debt and spending patterns established (or forced) by WW1 directly led to the collapse of the world economy once they played out.
- World War Two - without the disastrous mismanagement of the "peace" and subsequent (poor) realignment of countries at the ending of WW1, WW2 would never have occurred.
- The rise of National Socialism, and Adolf Hitler. The rise of Nazism is directly traceable to the Great Depression and the settlement of WW1.
- The Holocaust.
- The rise of the United States as a Superpower.
- The ceding of Western literary leadership from Europe to the United States. So many men of letters and talent died in WW1 that the new generation of influential writers and philosophers were almost exclusively American, simply because no one else was left alive. Thus, leadership in the arts passed to the US from Europe.
- Advent and justification for Total War, and the concept that civilians were legitimate targets for industrialized warfare.
- Change in government styles to concentrate power in National governments. That is, the movement towards nations run by highly complex bureaucracies where practically all political power resides at the National Government level (ie., the effective end to devolved sovereignty and the rise of strong central governments).
- Concept of global security organizations (and, more importantly, the ideas behind having a global community with actual supranational organizations)
- The impetus to create the Atomic Bomb.
- Movements of national self-determination
- The Cold War (and the various conflicts that arose from it: Vietnam, Korea, Afghanistan, the Cuban Missile Crisis)
- The seeming unending African civil wars was due to the breakup of Empires during the 1920s to 1940s.
- The establishment of Israel as a country it is now.
The list goes on and on...
It was a vast global war, but not quite as world-wide as World War II. Most of the fighting was in trenches in France, Poland, Russia, the Balkans, and parts of the Middle East, and on the Atlantic Ocean.
The suggestion that it was a "family feud" stems from the facts that three of the monarchs involved in the war were cousins by lineage or marriage: George V of the UK, Wilhelm II of Germany, and Nicholas II of Russia (who was killed in 1918 after the subsequent socialist revolution).
THE GREAT WAR WAS WORLD WAR 1
Things were looking good in the US. Europe was in chaos and needed both food and war material which could be cranked out in the states. The world was shifting from an agrarian to an industrial economy.