The Battle of the Atlantic was one of the crucial fronts in World War II; it was certainly a grueling fight from September 1939 until the tide turned in 1943. From the very first day, Germany wanted to sever these lifelines because it knew Britain was highly dependent on imported food and raw materials. Following the attack of the Wehrmacht in June 1941, the U.S.S.R. made clear it also needed imported equipment and supplies for its campaign. In return, the Allies had to secure mastery of the seas to sustain numerous secondary fronts, first in North Africa, then in Italy, and finally in Western Europe. The contribution of the United States, British, and Canadian navies was key to overcoming the crushing losses given by German U-boats and Luftwaffe bombers; the outcome hung in the balance until 1943.
From the American point of view, the Battle of the Atlantic passed through three distinct phases. Initially, the United States continued to pursue a policy of nonbelligerence while unobtrusively building up its naval forces. This culminated in the “Two-Ocean Navy” legislation in the summer of 1940 and finally, by President Franklin Roosevelt’s efforts in support of Britain. In August 1940, he manipulated an agreement to lend older destroyers in return for the right to use British bases in the Western Hemisphere. The Lend-Lease Act of March 1941 went even further, allowing a hard-pressed Britain to borrow vital equipment and materials. By the summer of 1941, U.S. troops had bases in Greenland and Iceland.
At this stage, Germany tried to avoid a direct conflict with the American navy. Tensions were climbing in the months leading up to Pearl Harbor, however. On September 4, 1941, a German submarine—attacked by a British plane—fired torpedoes at the USS Greer (DD 145) south of Iceland. Greer responded with 19 depth charges after which President Roosevelt ordered Navy crews to fire upon German U-boats on sight. The sinking of the USS Reuben James (DD 245) by U-552 on October 31, 1941, was the first lost U.S. Navy ship to enemy action in WWII.
While the Navy was better prepared than it had been in September, it was still unready for the German onslaught of the Battle of the Atlantic’s second phase. German U-boats announced their presence off the U.S. eastern coast by sending the steamer Cyclops to the bottom on January 12, 1942. Operation Drumbeat entailed incessant attacks by German submarines on tankers and merchantmen that the Navy was unable to protect because it had too few destroyers and subchasers. In the January through April months, German submarines sank over 80 merchantmen off the East Coast and 55 north of Bermuda. By May, convoy systems and increased naval and air patrols forced the U-boats to divert their activity into the Gulf of Mexico and the Caribbean.
In the fall of 1942, American escort groups safely delivered 100,000 troops and their equipment in support of Operation Torch in North Africa. But weakly protected areas continued to be exploited by German U-boats until a third phase began in May 1943. British and Canadian forces had, by then, stiffened their defenses for North Atlantic convoys, while Admiral Ernest J. King, as commander of the Tenth Fleet, led innovative antisubmarine efforts. Radar improvements and the employment of very long-range scout and bomber aircraft closed gaps submarines had previously used. Increased use of escort carriers and destroyers, together with British intercepts of German communications, enhanced the chances that the Allies would be able to repel a U-boat threat. American industrial output of naval vessels and merchantmen was finally paying off.
Indeed, by mid-1943, the tide had turned decisively. German U-boat crews still fought hard, but were now at a distinct disadvantage that gave Allied planners more confidence to push through land campaigns in Europe. The victory of the Battle of the Atlantic was gained by the Allies through many innovative ideas and a never-give-up spirit after relearning key lessons from World War I.
The sinking of the USS Reuben James on October 31, 1941, stands out as one of the more pointed reminders of the sacrifices. It was the first American warship lost in World War II, and its sinking showed that the struggle had spread, foreshadowing greater American involvement, which finally came a few months later with the raid on Pearl Harbor.