5 - The Allied response to the German submarine

Summary

It was not only on land on the Western Front that Britain and France had difficulties. The alliance was vulnerable at sea also. The risk came not from defeat in a surface battle. Jutland proved that there was no need to defeat the German High Seas Fleet; it could be contained in harbour. It was the Allied and neutral merchant fleets that were at risk. If enemy submarines were successful they might interdict supplies of coal and raw materials that the French needed desperately for their enormous munitions effort. The British needed food and grain imports from the Empire and the Americas.

On the eve of war, four out of every five slices of bread consumed in the British Isles were made with imported flour. Three of those five slices were spread with imported butter. Britain's dependence on imported foodstuffs was huge, and safeguarding the far-flung trade routes represented an enormous challenge for the merchant marine and the Royal Navy. That dependence was recognised well before August 1914, and, immediately after the declaration of war, measures were taken to protect supplies of wheat and sugar. Then industrial mobilisation created the need for imported raw materials that competed with foodstuffs for tonnage. If morale was to be maintained and workers fed adequately, measures had to be taken to control profits, such as those made by shipowners increasing freight charges. The Excess Profits Tax was one such measure.

In France the problems were different, but just as acute.