It was World War I that saw the development of the submarine as an effective weapon of war. The German submarine arm caused a threat to the British Allies in World War I, by the cutting of maritime supply routes that the British forces were depending upon (Jordan, 8). During the First World War the trade routes were ever so important because they consisted of foodstuffs that the British agriculture could not replace if the supply route was cut (Jordan, 8). It was the German submarine campaigns of World War I that influenced the German naval strategy of World War II. Without the naval campaigns of World War I the German submarines would not have made the dramatic impact that they did in the Second World War. The German submarine impact was seen in the cutting of the British lifelines as was done in the First World War. The German submarines also recorded large numbers of victories in United States waters. The German submarines were controlling the wars in the Oceans until the allied forces began to attack back with convoy systems, technology and air support. These factors would lead the strong German navy to defeat. The German navy would be defeated but only after they had recorded record number victories.
As was done in World War I the German Navy's first line of business was to limit the British resources. The first attack in engaging this campaign came not more than ten hours after Prime Minister Neville Chamberlains announcement that the war had begun (Pitt, 8). The first victory that came to the German U-boats was over the British liner Athenia (Pitt, 8). The German submarine force was also known as the Sea Wolves, and they struck time and time again on the merchant shipping that was vital to Britain's economic survival (Pitt, 8). In order for Britain to make any contribution to the war, and even to feed the people of there economy, it was essential for them to have control of the seas and the trade routes (Pitt, 17).