Answer:
The factors that contributed to the outbreak of World War I
Step-by-step explanation:
The reason for the outbreak of World War I was European countries as they began to form alliances with other countries after the assassination of the heir of Austria-Hungary Archduke Franz Ferdinand. Imperialism, Militarism, alliances, and Nationalism were the cause of the war. The growing desire and competition in Europe led to an increase in disputes that helped push them into WWI.
European nations suffered massive casualties in the wars because of advanced technology and weapons such as machines guns, submarines, planes, tanks, grenades, chemical weapons, etc.