The Industrial Revolution promoted efficient manufacturing and improved weaponry. As new alliances formed and many nations felt threatened by their neighbors, decisions were made to increase the size of their militaries for protection.
Alliances between major countries in Europe formed based on colonial rivalries and common interests.
Triple Alliance- Germany, Austria, Italy
Triple Entente- Russia, France, Great Britain
A rise in nationalism during the 19th century aided in the breakdown of empires, like Austria and the Ottomans, into unified and independent nations like Italy, Germany, Greece, and more. Nationalism also has an exclusive element that led many nations to prohibit certain people from being citizens.
New imperialism of the 19th century created colonial rivalries among European nations. Specifically, the Partition of Africa created new tensions and built upon old tensions from previous European conflicts.
The assassination of Archduke Franz Ferdinand of Austria by the Serbian nationalist group, the Black Hand, forces conflict in the Balkan states that had been stirred by the Bosnian Crisis.
The Moroccan Crisis beginning in 1905 expanded the old rivalry between France and Germany when Germany helped Morocco begin an independence movement against France. This rivalry began during the Franco-Prussian war.
The Bosnian Crisis of 1908 started when Austria expanded into the Balkan region, annexing Bosnia and Herzegovina. Not only did Serbia fear they would be annexed next, they also had their dreams of uniting these same territories under Serbian rule ruined.
No single issue above could have caused WWI, but combined, tensions seemed insurmountable and combined with an alliance system, forced most European nations to choose a side when, on June 28, 1914, a Serbian nationalist group assassinated the heir to the Austrian throne on a visit to Sarajevo, Bosnia. His wife, Sophie, and their unborn child were killed as well.
This assassination forced Austria to declare war on Serbia. Serbia’s ally, Russia, then declared war on Austria. Germany then wrote a “blank check,” promising unlimited support to Austria, and declared war on Russia. Finally, France and Great Britain joined the side of Russia through the Triple Entente.
Source: Canadian History Class Website
Germany comes within 30 miles of Paris, France during the Battle of the Marne and France stops them. The German plan for war with France was called the Schlieffen Plan and the goal was to sneak through Belgium to attack France. However, the French troops were ready. Trench warfare began in 1914 and lasts through the end of 1918.
Trench Warfare involved a system of trenches dug into and under the ground. The space between each trench was called “No Mans Land,” as most who entered, were killed by mines, machine guns, high caliber weapons, or chemical gases. Life in the trenches was equally as dangerous, as many contracted diseases, such as gangrene, or were killed when the opposing trench advanced.
Russia and Romania held off advances from Germany, Austria-Hungary, and the Ottoman Empire. Transportation of supplies was made more efficient by the use of rail lines on each side.
Conflict ended in 1917 when the Russian Revolution’s new government signed the Treaty of Brest-Litovsk, ending the war involving Russia.
The United States joins the war after a series of events keeps them from their original policy of isolation. Germany’s use of unrestricted submarine warfare and the sinking of the Lusitania had many Americans interested in joining the war efforts. However, the final straw was the Zimmerman telegram- Germany’s attempt at involving a Mexican invasion of the US southern border to keep them from entering the European conflict.
Germany asked the French, British and the US to negotiate an armistice to end the war. Germany had suffered mass casualties since the US entered the conflict, and they were unable to continue fighting due to extreme economic conditions in Germany. The Armistice was negotiated, as well as the Treaty of Versailles at the Paris Peace Conference in 1918.