There are many legacies of WWI. Three of these legacies have to do with the paid price of human lives, the impact on the economy, and the development of new technologies.
A tremendous price in human life was paid. Due to the war, 8.5 million soldiers died, and 21 million soldiers were injured. Many civilians were killed. In essence, an entire generation was destroyed.
There was a devastating economic impact. Treasuries were drained of European countries. It is estimated the war cost $338 billion. Farmland, homes, villages, and towns were destroyed.
New technologies were developed. Poisonous gas was developed by the Germans and caused blindness, blisters, and death by choking. Tanks were first used by the British at the Battle of Somme in 1914. Machine guns were improved upon during this time. Military aviation was used for the first time because this was the first war in which planes were used.
The main causes of WWI are militarism, alliances, imperialism, and nationalism. Militarism is the building up of a country's military. For example, Germany competed with the United Kingdom to build battleships. Alliances are a bond between two or more nations. Two examples of alliances are the Triple Alliance and the Triple Entente. The Triple Alliance included Germany, Austria-Hungary, and Italy. The Triple Entente included France, Russia, and Great Britain. This is when a country takes control of a weaker territory or country. Germany was building an empire in Africa, but Great Britain did not like this. Nationalism means to have pride in one's own country. For example, Slavs wanted to be free of Austrian rule.