11 h 10 m, 22 fev 1915 ano - Germany declared unrestricted submarine warfare (first declaration) - Feb 22, 1915

Descrição:

Unrestricted submarine warfare was first introduced in World War I in early 1915, when Germany declared the area around the British Isles a war zone, in which all merchant ships, including those from neutral countries, would be attacked by the German navy.

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