"Of the 10,583,755 tons of Japanese naval and merchant vessels sunk during World War II, 9,736,068 tons were sunk by United States forces, 5,320,094 tons being accounted for by United States submarines alone. Our submarines were doing to the Japanese in the Pacific what the German U-boats were doing to Allied shipping in the Atlantic; but the industrial power of the United States was almost limitless, while that of Japan was not. Until the closing months of 1942 the German submarines continually reduced the available total of Allied tonnage, but thereafter both by the improved effectiveness of antisubmarine measures and the stupendous output of American and British shipyards, Allied shipping constantly increased. Although approximately 23,351,000 tons of Allied shipping were sunk by German U-boats between 1939 and 1945, new construction reached the total of 42,485,000 tons so that the final balance sheet in the Atlantic showed a net gain of 19,134,000 tons. Japanese losses, not being offset by comparable new construction, were in large part final. Thus as the enemy's links with his extended positions and overseas sources of logistic strength in the Pacific were being weakened by our submarines, his very hold upon those conquests was challenged by the industrial productivity of the United States."