Explain how various countries entered World War I in Europe. 

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mkoren eNotes educator| Certified Educator

There were various reasons why each country entered World War I in Europe. Europe had been heading toward war as the issues of imperialism, nationalism, and militarism were growing in Europe.

Austria-Hungary started the hostilities. After Franz Ferdinand, who was the heir to the Austro-Hungarian throne, was assassinated in Sarajevo in 1914, Austria-Hungary gave a list of demands to the Serbian government. Austria-Hungary believed that Serbia had some responsibility for the assassination of Franz Ferdinand. When the Serbian government could not meet all the demands that Austria-Hungary placed on it, Austria-Hungary declared war on Serbia. Russia and Serbia had been allies for many years. As a result, Russia declared war on Austria-Hungary.

Other countries also entered the war. Germany had promised Austria-Hungary that it would provide support if Austria-Hungary got attacked. Thus, Germany declared war on Russia. Since France and Russia had an alliance, Germany and France declared war on each other on the same day. Great Britain didn’t join the war until Germany invaded neutral Belgium. When that occurred, Great Britain declared war on Germany. The United States entered World War I in 1917 after Germany began to sink our ships without warning them. This violated our rights as a neutral nation to trade with other countries, including countries that were at war.

There were various reasons why some countries joined World War I.