On April 6 the United States declared war on Germany. On April 13 we received information from Washington that the Navy Department was arranging to co-operate with our forces for the protection of trade in the West Atlantic should any enemy raiders escape from the North Sea, that six United States destroyers would be sent to European waters in the immediate future, and that the United States would undertake the protection of trade on the west coast of Canada and North America as well as in the Gulf of Mexico. It was further indicated that the number of United States destroyers for European waters would be increased at an early date. The vital importance of this latter step was being constantly urged by Admiral Sims. When Mr. Balfour's mission left for the United States in April, Rear-Admiral Sir Dudley de Chair, the naval representative on the mission, was requested to do all in his power to impress on the United States Navy Department the very urgent necessity that existed for the immediate provision of small craft for anti-submarine operations in European waters and for the protection of trade. He was informed that the position could not be considered satisfactory until the number of trawlers and sloops available for patrol and escort duty was greatly increased and that a total of at least _another hundred destroyers was required_. It was pointed out that difficulty might arise from the natural desire of the United States Government to retain large numbers of small craft for the protection of shipping in the vicinity of the United States coast, but it was at the same time indicated that our experience showed that the number of submarines that the Germans could maintain on the western side of the Atlantic was very small, and that the real danger therefore existed in European waters. Admiral de Chair was asked amongst other matters to emphasize the assistance which United States submarines could render on the eastern side of the Atlantic, where they would be able to undertake anti-submarine operations, and he was also directed to endeavour to obtain assistance in the production of mines, and the provision of ships for minelaying work. Great stress was, of course, laid upon the very important question of a large output of merchant ships and the necessity for repairing and putting into service the German merchant ships interned in U.S. ports was urged; directions were also given to Admiral de Chair to ascertain from Mr. Schwab, of the Bethlehem Steel Company, and other firms, to what extent they could build for the British Navy destroyers, sloops, trawlers and submarines, and the rapidity of such production.