Washington, D.C. • October 2, 1939
On January 31, 1939, President Franklin D. Roosevelt held a closed-door meeting with the Senate Military Affairs Committee at the White House. Reportedly FDR made the comment that “the frontier of the United States is the Rhine,” meaning France’s eastern border with Nazi Germany. When the statement was leaked to the press, the hubbub in America’s isolationist circles was deafening. The president denied having made any such statement, calling the newspaper article “100% bunk.” However, one month after the outbreak of war in Europe in September 1939, Roosevelt was in a much stronger position to define the country’s eastern frontier vis-à-vis the isolationists and those who favored complete U.S. neutrality, although the American frontier was nowhere near Europe.
On this date in 1939, as Great Britain and Nazi Germany fought each other for control of the transoceanic highway to and from the British Isles (Battle of the Atlantic), Roosevelt declared a region of the Atlantic adjacent to the Americas as the Pan-American Security Zone. Within the zone, which initially extended from 300 to 1,000 nautical miles offshore, all hostile actions by belligerent powers—meaning Nazi Germany and Fascist Italy—were forbidden. U.S. naval and air patrols escorted and actively protected convoys sailing to and from Europe within this neutral zone, even broadcasting unencrypted U‑boat sightings, which could be intercepted by British warships. Naturally, shadowing U‑boats and broadcasting their locations incurred the resentment of the German Kriegsmarine, alarmed over America’s warped sense of “neutrality.” On April 18, 1941, Roosevelt extended the Pan-American Security Zone by another 1,300 nautical miles (altogether 2,300 nautical miles from New York City) to a point just short of the mid-Atlantic Danish dependency of Iceland, a major transatlantic convoy staging area. The gap in the zone was closed when Iceland severed its relationship with its German-occupied mother country and permitted the U.S. to garrison the island in July 1941.
Protecting the Transatlantic Pipeline Between the Americas and Europe
Left: After the German invasion of Poland on September 1, 1939, President Franklin D. Roosevelt immediately declared America’s neutrality. Four days later the U.S. organized a so-called Neutrality Patrol, consisting of naval and air units whose mission was to track and report the movements of any warlike operations of belligerents in the waters of the Western Hemisphere. In this 1940 photo U.S. Navy Vought SBU‑1 Corsair dive bombers fly the Neutrality Patrol near Norfolk, Virginia.
Right: A U.S. Navy Vought SB2‑U Vindicator scout bomber from the U.S. aircraft carrier Ranger flies antisubmarine patrol over a convoy en route to Cape Town, South Africa, November 27, 1941.
Left: Escorts and merchant ships at the Hvalfjord (Hvalfjörður) naval base, Iceland, late June 1942. During World War II nearly one third of the world’s merchant shipping was British. Out of 36,000 merchant seamen who lost their lives between 1939 and 1945, over 30,000 were from the British Merchant Navy. More than 2,400 British ships were sunk out of the total of 2,900 Allied ships lost, or a loss of 14.6 million gross tons. A little over 9,500 U.S. merchant marines died at sea, in POW camps, or of their wounds out of the roughly 243,000 who served. (The U.S. government never kept accurate records for its merchant marine.) Most of the ships sunk during the Battle of the Atlantic were not in convoys, but sailing alone, or had become separated from convoys.
Right: Officers on the bridge of an escorting British destroyer keep a sharp look out for enemy submarines, October 1941. The Battle of the North Atlantic was the longest continuous military campaign of World War II. Lasting six years, the battle involved thousands of ships and stretched over hundreds of square miles of ocean in a series of more than a hundred convoy battles and as many as a thousand single-ship encounters. Tactical advantage shifted to and fro over the years as new weapons, tactics, and countermeasures were developed by both sides. Gradually the Allies gained the upper hand, first driving German surface raiders like the pocket battleship Graf Spee and the converted auxiliary cruisers Atlantis and Pinguin from the seas by the end of 1942 and then decisively defeating the U‑boats in a series of convoy battles between March and May 1943.
Left: An unnamed U-boat shells a merchant ship that had remained afloat after being torpedoed (no date). The focus on U‑boat successes, “ace” skippers and their scores, the number of convoys attacked, and the ships sunk obscures the fact that during the Battle of the Atlantic only 10 percent of transatlantic convoys were ever attacked, and of those attacked only 10 percent on average of the ships were lost. Overall, more than 99 percent of all ships sailing to and from Great Britain during World War II did so safely.
Right: The 8,046-ton U.S. tanker Dixie Arrow was torpedoed by U‑71 on March 26, 1942. The ship is shown crumbling amidships under the heat of fire. Between June 1, 1941, and May 31, 1943, the U‑71 carried out ten war patrols. Operating out of the huge U‑boat pens at St. Nazaire in occupied France, U‑71 on her fifth foray sank 38,894 tons of shipping between March and April 1942. She survived combat duty to be scuttled on May 2, 1945, in Wilhelmshaven, Germany, several days before the country’s surrender.
Left: A Grumman TBF Avenger of the Royal Navy’s Fleet Air Arm fires its machine gun on the conning tower of U‑288 during a convoy run to the Soviet Union, April 3, 1944. The U‑boat was eventually sunk by rockets and depth charges. Forty-nine men died; there were no survivors. The Kriegsmarine lost a total of 783 submarines and 30,000 sailors during the war. Despite their best efforts, German submarines failed to stop the flow of strategic supplies to Britain. Between existing Allied merchant ships, U.S.‑built Liberty ships (totaling 38.5 million tons), and British-built Empire ships, the Allies launched millions more ship tonnage than the 14 million tons of shipping lost to the U‑boat menace.
Right: At the height of the Atlantic campaign, U‑boats failed to hinder or even detect the U.S. invasion fleet headed to North Africa in November 1942 (Operation Torch), and they failed to prevent the buildup of troops and supplies needed for the D-Day landings in Normandy, France, in June 1944. As early as May 1943, when a fifth of his U‑boats was sunk in “Black May,” Grand Admiral Karl Doenitz conceded that Germany had lost the Battle of the Atlantic.
Battle of the Atlantic, 1939–1945: Contemporary Footage