Final answer:
The long-term causes of World War I were Militarism, Alliances, Imperialism, and Nationalism. The Alliance system, however, is not considered a long-term cause.
Step-by-step explanation:
When considering the long-term causes of World War I, four major factors come to mind: Militarism, Alliances, Imperialism, and Nationalism. So, the option that is not considered a long-term cause of World War I is the Alliance system. Although alliances played a significant role in the outbreak of the war, they are considered more of a short-term cause, as they were formed in response to the tensions created by the long-term causes.