Naval Blockades and Submarine Warfare

October 25, 1939

Report Outline
British-German War Measures, 1914 and 1939
Law of Blockade and Contraband of War
World War Blockades and U-Boat Warfare
Developments of Present European War

British-German War Measures, 1914 and 1939

In The Present European conflict, Great Britain has drawn upon her World War experience to institute within a few weeks measures of blockade against Germany which were developed in the last war only over a period of months or, in the case of some measures, as long as two years. The British government, moreover, proceeded immediately to arm the whole British merchant marine against submarine attacks, while Germany came to an early decision to wage unrestricted submarine warfare against enemy shipping. Thus, although the effects of such measures have not yet been fully felt, the war, so far as concerns the phases of blockade and resistance to blockade, threatens to be carried on in its early stages with a degree of intensity not reached in the last war until the third year.

Announcement that German submarines would attack enemy merchantmen without warning followed disclosure of Great Britain's extensive ship-arming program. The German government took the view that the armed merchantman, since it was capable, even though armed theoretically only for defense, of sinking a submarine, was in effect a war vessel and therefore not entitled to immunity from attack at sight. It was proposed in the last war that all merchant ships go unarmed in return for a commitment by the German government that its submarines observe the traditional rules of visit and search and refrain from sinking such ships without making provision for the safety of those on board.

Observance of such an agreement would have saved the lives of noncombatants but might have resulted in greater merchant shipping losses, since, if submarines had been relieved of all risk in approaching enemy merchantmen, they could presumably have taken a greater toll of such vessels. Great Britain's decision to arm her merchantmen in the present war indicates a belief in the efficacy of such action in reducing the submarine menace.

ISSUE TRACKER for Related Reports
U.S. Navy
Jul. 23, 1976  Navy Rebuilding
Mar. 06, 1968  Sea Power and Global Strategy
Oct. 06, 1945  Army-Navy Consolidation
Oct. 02, 1941  Undeclared Naval Warfare
Oct. 25, 1939  Naval Blockades and Submarine Warfare
Nov. 20, 1935  American Naval Policy
Nov. 19, 1934  Naval Limitation and Pacific Problems, 1921–1936
Oct. 27, 1931  The Proposed Naval Holiday
Jul. 25, 1930  Military and Naval Expenditures
Jan. 16, 1930  The London Naval Conference
Sep. 28, 1929  The Anglo-American Naval Situation
Feb. 13, 1928  The 1928 Naval Building Program
International Law and Agreements
War and Conflict
World War II