Great Britain's economic blockade of Germany in World War I, 1914--1919

Great Britain's economic blockade of Germany in World War I was one of the key elements in the Entente victory. For two centuries preceding the Great War, the British were the masters of using blockades to achieve victory in war. Despite this experience, the World War I blockade was not a well thought-out policy at the outbreak of hostilities. The blockade evolved slowly and was not effective until the last year of the war. This process resulted from changes in the relationship between the British Foreign Office and Admiralty that supplanted the Royal Navy's traditional leadership role in blockades in favor of direction from the civilian branch of government. The British Foreign Office championed international law, which produced legislation that compromised Britain's belligerent rights governing naval blockades.; The struggle between the primacy of international law and military expediency lasted for nearly two years. The British tried to reconcile their pre-war stance as champion of neutral rights with measures necessary for a successful blockade. Throughout 1914 and 1915 the blockade continued to lack the means necessary for it to be effective. Only in 1916 did it have the potential to be a decisive factor in the defeat of Germany. Pressure from Britain's French ally, the Royal Navy, Parliament, British popular opinion, and the Admiralty itself forced the British government to abandon its defense of neutral rights over the interests of the state.; The entry of the United States as a belligerent on the Entente side in April 1917 initiated the final evolution of the blockade that rendered it an effective offensive tool. The Entente and the United States tightened the blockade with resulting crushing effect on Germany. By November 1918, it was evident that the blockade was a prime factor behind the Entente victory. This knowledge reinforced the decision to retain the blockade in the months following the armistice in order to force favorable terms from Germany. In both the war and the peace, the blockade held a critical role as one of the most important institutions of World War I.