The assassination of the archduke Franz Ferdinand caused Kaiser of Germany to step in and help Austria punish Serbia. There is an influence of Nationalism because they are coming in and pushing the Serbs around. Because of this, Russia, Serbia, France, and Britain went to war. Not to long after this, people used war to solve problems.
Another cause of war was Europe's rapidly expanding economy. Along with change
comes higher demand because laborers wanted wealth and power to benefit everyone. People called for reforms, and for women to have the privilege to vote. With Europe expanding rapidly, Germany started to become pretty powerful. This put Great Britain on alert and forced them to make agreements with arch nemesis Russia and France. Europe was now divided.
Last but not least, a major cause of World War I is when Austria-Hungary declared war against Serbia. With all of the countries having allies close by, the result of war between Austria and the Serbs ended up causing war all over Europe . The countries that got dragged into the war were Russia, Germany, France and Britain. WWI ended up being a war that will be remembered for centuries to come.
Most of the major events that happened during World War I were either influenced by Militarism, Nationalism, Imperialism, or the Alliance System. Germany used militarism as a way to become stronger and prepare themselves for war. They became a pretty powerful country in which they even had Britain feel threatened. Militarism was a pretty big deal in WWI as germany forced themselves into other countries. Although militarism is a major cause of WWI, without Nationalism, Militarism wouldn't have played such a big part.