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unrestricted submarine warfare
Germany's unrestricted submarine warfare
it was Germany.
unrestricted submarine warfare
Germany's submarine warfare was unrestricted. These attacks led to World War I.
Help end the British blockade
Germany practiced unrestricted submarine warfare.
it referred to sinking ships
To get the blockade lifted.
Unrestricted Submarine Warfare.
American enterance into WWI.
Germany resumed unrestricted submarine warfare in 1915. The Germans declared the waters around the British Isle a war zone. The would attack any merchant ship entering that area.