The Prize: The Epic Quest for Oil, Money, and Power

by Daniel Yergin

But in the last days of March, the scales tipped dramatically, and just in time. First, there was a decisive shift in the cryptanalytic balance; the Allies thoroughly broke the new U-boat codes, while at the same time they successfully closed off their own convoy ciphers to the Germans. Then the British and Americans added a new coordinated counteroffensive capability to the convoy system that included support groups designed to attack the U-boats. The Allies further improved their radar, and they also introduced newly developed longrange aircraft that could, at last, provide coverage over that part of the Atlantic previously inaccessible to air protection. The tables were abruptly and finally turned. In May 1943 alone, 30 percent of the U-boats at sea were lost. A chastened Admiral Doenitz was forced to report to Hitler: “We are facing the greatest crisis in submarine warfare, since the enemy, by means of new location devices …makes fighting impossible, and is causing us heavy losses.” On May 24, Doenitz ordered the U-boats to withdraw to safer areas. Though he denied it at the time, he was calling off the submarine campaign in the North Atlantic. Allied convoys—carrying their vital cargoes of oil, other goods, and troops—could now cross the Atlantic in reasonable safety. A combination of technical innovation, intelligence, organization, new tactics—and persistence—finally assured an abundant flow of oil from America to Britain and on to Europe and the Soviet Union. The p...