Timeline Thursday 4 February 1915

Events on Thursday 4 February 1915 2

• 1915 Germany declares unrestricted submarine warfare German U-boats authorized to sink merchant ships without warning around Britain On 4 February 1915 Germany declared the waters around the British Isles a war zone in which Allied merchant ships would be sunk without warning. The policy, which took effect on 18 February, marked an escalation of submarine warfare that would later draw the United States toward war.
• 1915 Unrestricted submarine warfare declared Berlin, Germany Germany announced it would sink merchant ships around Britain without warning, including neutral ones.