Due to the limitations, imposed by the Treaty of Versailles, the number of warships to be constructed in Germany, the Kriegsmarine was far smaller than of her rivals Great Britain and France on the eve of the Second WorldWar. In order to be on somewhat equal terms with the Royal Navy and the Marine Nationale and to keep the British and French warships away from future German operations, the Germans devised a cunning tactic. As Great Britain was an island empire, she needed to import food and raw materials by sea. The French as well as the British depended on the sea lanes to maintain the economy of their colonies.