 The strength of the British navy, combined with the strength of the French Navy and later bolstered by the entry of Italy and the United States on the Allied side, ensured that Allied control of the Atlantic sea lanes was never seriously threatened and compelled Germany to pursue less costly alternatives, submarines, in particular, to project a measure of power on the high seas.In the Pacific, British and Canadian interests were assisted by having Japan as an ally.During World War I, the Imperial Japanese Navy had a North American Task Force.