Answer:
These are militarism, alliances, imperialism, and nationalism. Militarism drove countries into an arms race before World War I, and as they increased their military strength they would become more hostile to their enemies/rivals. Alliances forced countries that would normally have nothing to do with the war were dragged in due to their alliances, greatly increasing the number of fighting countries, which is part of how it became a "great war." Imperialism rose tensions because Imperial nations would continuously expand their territory, leading to higher tensions around Europe, because people were running out of space to conquer. Nationalism led to World War I because every country had their own beliefs that they were better than the others, leading to extremely high tensions.
