The destructive forces in which Nationalism can outbreak is both astounding and atrocious. Nationalism was created and pursued to help unite the country socially, economically, and culturally. However, what was meant to be advantageous lead to the centrifugal break down of the countries. Due to Nationalism, wars were incessantly being engaged because of arisen problems such as Imperialism, Militarism, and Exclusive Nationalism. Countries that were imperialistic began to extend their power over boundaries and commenced their supremacy over additional territories, causing hatred and bitterness, which eventually lead to rebellion and war. Militarism progressed due to the demand of a strong army, as they felt susceptible to attacks from other countries that were robust and had a powerful army as well, causing a massive explosion of weapons being produced and armies being heightened. Exclusive Nationalism did not support other ethnicities, prohibiting others from joining and coercing them to recede, including social Darwinism, which caused great tension between countries.
These build ups and disagreements would inevitably lead to war.
Imperialism began when European nations ruled smaller countries. As territories were being controlled, a race to amass other countries began. For example, France and Britain had many other colonies in Africa and Asia. With control of smaller countries, they were able to collect raw materials and produce cheap labor, greatly boosting their economic state. Italy and Germany began to become envious, and decided that they wanted a colonial empire as well. Of course, conflict began when two nations wanted the same country. There was no reasonable way to settle which country belonged to whom. The only way they were able to settle this was through war. Whoever was the strongest and won the war was the nation that was allowed to keep the country until a more powerful force could drive it out.