The four causes of World War 1 are Militarism, Alliances, Imperialism, and Nationalism. Militarism is the belief or desire of a government or people that a country should maintain a strong military capability and be prepared to use it aggressively to defend or promote national interests. Alliances is a pact, coalition or friendship between two or more parties. Imperialism is an unequal human and territorial relationship, usually in the form of a empire, based on ideas of superiority and practices of dominance and involving the extension of authority and control of one state or people over another. Nationalism is a belief, creed or political ideology that individual identifying with or becoming attached to ones nation. Alliances is a pact, coalition or friendship between two or more parties.
Militarism helped start the war because countries needed more land for their armies and they thought the fight would be over fast. Alliances helped start the war because one country would get in a war and then have another back them up, then the opposing side would also do that, then more and more counties join then the war gets bigger. Imperialism helped start the war because imperialistic countries wanted more land and exclusive trading rights with another country. Nationalism helped start the war because they thought the war would be over in a couple of months.
Unrestricted submarine warfare is the first,Unrestricted submarine warfare is a type of naval warfare in which submarine sink vessels such as freighters and tankers without warning, as opposed to attacks per prize rules, Unrestricted submarine warfare started in 1915. The second was the Lusitania, the Lusitania was a British ocean liner that was sunk by a German u-boat on May 7 1915, the death toll was 1198. The third is Sussex Pledge, the Sussex pledge was a pledge in World War I by Germany to the United States prior to the latter's entry into the war, the date it was May 4 1916. The Fourth is the Zimmerman Note, the Zimmerman Note is was a 1917 diplomatic proposal from the German Empire for Mexico to join the Central Powers, in the event of the United States entering World War I on the side of the Entente Powers, the note was intercepted on January 16 1917.