The correct answer to this open question is the following.
Nationalistic, totalitarianism, and imperialistic ideas were some of the most important causes that detonated the beginning of World War I in Europe. The ambition of political and military leaders, expansionists’ ideas, ethnics problems, and the hunger for power were reasons that confronted countries in battle. The consequences: millions of people were killed due to modern technology in weaponry, entire cities were destroyed, and nations became weak and vulnerable.
Modern weapons for that time such as tanks, machineguns, and chemical gases produced so much pain, destruction, and suffering. The war at the trenches also resulted in millions of casualties.
Under the flag of Liberalism and the protection of personal liberties, European countries tried not only to protect their nations but defend themselves from other “strange” forms of thinking from rivals or enemies.
Nationalistic ideas were so dominant at the time, that it was practically impossible to find respect and tolerance for other ethnicities and cultures in some European countries. When Nationalism made people believe that they were superior to other races, then the preamble of World War I was established. Nations felt that their history, traditions, language, and culture were superior to other rival nations and differences became problems, problems became conflicts, and conflicts became wars.
