While the Napoleonic wars went on, his job was to maintain the British maritime supremacy established at the battle of Trafalgar. In a state paper of February 1813 he pointed out that France, with the shipbuilding resources of the Netherlands and Italy at her disposal, would be able to construct a fleet to match Britain's if the struggle continued much longer. The point was underlined by complaints from the Duke of Wellington in Spain of inadequate protection for the convoys supplying him, especially after the outbreak of hostilities with the United States in 1812 unleashed hordes of American privateers on the Atlantic.