unrestricted submarine warfare
Anti-Submarine Warfare.
To get the blockade lifted.
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.
Enemy surface ships are the main target of submarine warfare
Germany hoped that submarine warfare would lead to war.
Anti submarine warfare
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Germany's submarine warfare was unrestricted. These attacks led to World War I.
USA
submarine warfare
Submarine warfare has existed since the early 1900's, and continues to this day. Though the last ship sinking by a submarine was in the Falklands War, the evolving missions of submarines have taken submarine warfare well beyond just sinking ships and submarines.
unrestricted submarine warfare
Germany's unrestricted submarine warfare
Anti-Submarine Warfare.
it was Germany.