America and Nazi Germany Waged an Undeclared Naval War Way before Pearl Harbor

America and Nazi Germany Waged an Undeclared Naval War Way before Pearl Harbor

The facts make it clear. 

As 1940 ended, Britain faced financial exhaustion, calamitous shipping loses, the systematic ravaging of England by the Blitz, and the expectation of a German drive through the Balkans. On the plus side, Britain had a naval alliance with the United States and coordinated naval operations with the United States Navy. Also, the “Arsenal of Democracy” was about to open its factories and treasury.

“Belligerent Neutrality”

Joint Chiefs of Staff talks suggested by Stark began on January 29, 1941. They lasted almost two months and resulted in clearly defined American assignments in the undeclared war. Before the meetings, Roosevelt set the guiding principles by which the American staff was to develop a combined strategy with the British. America’s military course would be conservative until its strength developed, and America would be ready to act with what was available. He also warned the Navy to be prepared to convoy.

At these secret meetings, the Americans committed the U.S. Navy to escorting North Atlantic shipping. In the final written agreement, the key passage read: “The principle task of the United States naval forces in the Atlantic will be the protection of shipping of the associated Powers [Britain, United States and invaded European nations].” Also, the British pledged that when America came into the war, covertly or overtly, Canadian naval forces would automatically come under American command. It meant a “neutral” nation would command the ships of a nation at war.

The name given to this undeclared status was “belligerent neutrality.” This meant the protection of the Atlantic convoy routes became part of the American security policy, although Roosevelt denied this fact to the press and public. The two staffs agreed upon further specific operations for the U.S. Navy, which included regular Atlantic patrols, the defense of Greenland, and providing escort for convoys halfway across the Atlantic to be turned over to the Royal Navy at the MOMP, the Mid-Ocean Meeting Point.

Historian Hanson Baldwin described U.S. assignments as a thinly disguised neutrality that became an unrestricted war at sea. With the Navy assignments established, Roosevelt directed that the Navy’s patrol force be greatly expanded, renamed the Atlantic Fleet, and brought to a state of readiness. Roosevelt met with Admiral King at Hyde Park to work out detailed operational plans.

Stark’s reaction to the resulting directive was to tell King, “This step is, in effect, a war mobilization.” In a letter to all his fleet commanders, Stark wrote, “My own personal view is that we may be in the war (possibly undeclared) against Germany and Italy within two months.”

The First Shots of America’s Undeclared War

Casco Bay, Maine, was developed as a U.S. destroyer base. In mid-February, U.S. Marines raised the American flag over a desolate village called Argentia, in Newfoundland, and the U.S. Navy took an active role in convoy protection. Also in February, the Atlantic force attained fleet status and received reinforcements from the Pacific: the carrier USS Yorktown, three battleships, USS New Mexico, USS Mississippi, USS Idaho, and several cruisers and destroyers.

With the passage of Lend-Lease in March 1941, the pace of America’s involvement in the naval war increased. In March, American officers arrived in Britain to select bases in Scotland for American destroyers. On March 17, the Coast Guard cutter Cayuga left Boston with the Greenland Survey Expedition to locate military airfields, seaplane bases, radio stations, meteorological stations, and aids to navigation and to furnish hydrographic information from Greenland.

On April 4, American shipyards became available to British and Allied vessels for repair and refitting. Just five days later the British battleship, HMS Malaya, arrived in New York for repairs, paid for by Lend-Lease funds. On April 7, the U.S. naval base on the Crown Colony of Bermuda was commissioned. A de facto U.S. protectorate over Greenland became formally legalized on April 9. The president told the American public that a loss of Greenland or Iceland “would directly endanger the freedom of the Atlantic and our own American physical safety.”

The U.S. Coast Guard established the Greenland Patrol in June and July 1941. By September, Army engineers had constructed 85 buildings and three miles of access roads. The jeeps that were flown in were Greenland’s first automobiles. Soon a civilian contractor’s force arrived to begin work on the airfield itself. BLUIE West 1 was to become the major U.S. Army, Navy, and Coast Guard base in Greenland. Thousands of aircraft would stop there for refueling on their way to Britain. The day after the announcement of the Greenland occupation, the first shots fired by an American warship occurred.

The destroyer USS Niblack dropped depth charges on a U-boat while conducting rescue operations near a torpedoed Dutch freighter off the coast of Greenland on April 10, 1941. This was the first combat action taken by an American naval vessel against the Axis powers. Subsequently, the patrol zone was extended to the 26th longitude, and Roosevelt requested that the British Admiralty notify American naval units in “great secrecy” of its convoy dates, plans, and destinations, “so that our patrol units can seek out any ships or planes of aggressor nations operating west of the new line.” On April 18, the Navy Department authorized the construction of a destroyer base at Londonderry, Northern Ireland, and one on the west coast of Scotland, along with seaplane bases in Northern Ireland and northern Scotland. American forces were now planted on territory clearly in Europe without a declaration of war.

Operation Plan 3-41

On April 18, Admiral King issued Operation Plan 3-41, which officially designated the water west of the 26th longitude, just west of Iceland, to be part of the Western Hemisphere and stated that any transgression of that line by the Axis was to be viewed as unfriendly. Operating under this order, the Coast Guard cleaned out the German weather stations on Greenland. These turned out to be the first land combat actions of the undeclared war.

America replaced British merchant losses in the Atlantic. Fifty first-class tankers were transferred to the British maritime shuttle, replacing the 42 British tankers already sunk. Later, an additional transfer of 75 Norwegian and Panamanian tankers to the British doubled their tanker fleet. In mid-May, Churchill assessed America’s impact in a memo to South African General Jan Smuts, which stated, “We shall certainly get increasing American help in the Atlantic, and personally, I feel confident our position will be strengthened in all essentials before the year is out.” But it was also in May that the first American merchantman was sunk in the Atlantic. The undeclared war had its first casualty.

More and more each day, American forces and personnel became involved in combat. The Coast Guard cutter Modoc was in sight of the naval duel between the battlecruiser HMS Hood and German battleship Bismarck. In fact, it was an American adviser, Ensign L.B. Smith, who spotted Bismarck on May 26 while piloting a British seaplane. That contact led to the German battleship’s sinking.

Roosevelt used the sinking of Bismarck to declare an “unlimited emergency.” This now meant the U.S. Navy would patrol all of the North and South Atlantic. On June 1, the South Greenland Patrol began to protect the sealanes from Cape Brewster to Cape Farewell to Upernivik. On June 7, the president approved the “Basic Joint Army and Navy Plan for Defense of Greenland,” which included a second patrol, the Northeast Greenland Patrol. The patrol went into effect on July 1, when two veteran Coast Guard ships, the Bear, built in 1874, and the Northland, built in 1926, sailed on the first patrol. Everything available was used, as Admiral King had suggested.

“Practically an Act of War”

The American Fleet complicated Germany’s only threat in the Atlantic: the U-boats. Despite Hitler’s restrictions, the Germans began to zero in on American warships. On June 20, 1941, U-203 tracked and tried to get into a firing position against the battleship USS Texas in the area of sea where the neutrality zone and Hitler’s war zone overlapped. Although U-203 failed, another U-boat sank the merchantman SS Robin Moore on June 27. But the coordination between American and British naval staffs enabled them to reroute most of the convoys from the paths of the German submarines. The rerouting worked so well that many of the U-boat sightings were only of American warships, which they were not allowed to attack. In July, the United States occupied Iceland, a European territory. This was tantamount to a declaration of war against Germany.

On July 7, the U.S. Navy landed the Marines professionally and with dispatch. Roosevelt ordered a war zone around Iceland and notified Stark and Army Chief of Staff General George C. Marshall that “the approach of any Axis force within 50 miles of Iceland was to be deemed conclusive evidence of hostile intention and therefore would justify an attack by the armed forces of the United States.”

Admiral King immediately followed the presidential order with “Special Instructions Concerning U.S. Navy Western Hemisphere Defense Plan No. 4—(WPL-51)” on July 25, which ordered the American Fleet to escort American merchant ships traveling to Iceland. This was later amended to include “shipping of any nationality.” The next important contingent to arrive on Iceland, on August 6, was U.S. Navy Patrol Wing 7, a contingent of seaplanes.