The United States entered World War II as a result of the Dec. 7, 1941, Japanese attack on Pearl Harbor and other American military bases on the Hawaiian island of Oahu.
The next day, President Franklin Delano Roosevelt, known as FDR, addressed a joint session of the U.S. Congress. Declaring the attack “a day that will live in infamy,” he asked lawmakers “for a declaration of war against the empire of Japan.” That same day, the Senate voted unanimously to declare war against Japan. The House of Representatives concurred. There was only one dissenting vote, Rep. Jeanette Rankin, a Republican from Montana.
Three days later, Italy and Germany declared war on the United States. Benito Mussolini was first. Appearing on the balcony overlooking Piazza Venezia in the center of Rome, he declared that Italy would stand fast “with the powers of the Pact of Steel.” A few hours later, Adolf Hitler, addressing the Reichstag, declared that, despite his efforts to avoid war with the U.S., under the Tripartite Agreement of Sept. 27, 1940, Germany “was obligated” to join its Italian ally to support Japan. In reality, the Pact of Steel required only a declaration of war in the event one of the parties was attacked. Neither Mussolini nor Hitler was obligated to declare war on the U.S.
The next day, Dec. 11, Congress responded by formally declaring war against Germany and Italy. The resolution passed without debate. Once again, Rankin voted against the resolution. In the meantime, the leadership of the Democratic and Republican parties announced that they would “adjourn politics” for the duration of the conflict. That same day, Congress ratified a law allowing U.S. armed forces to be deployed anywhere in the world.
Ten days later, British Prime Minister Winston Churchill arrived in Washington, D.C., for a series of meetings with FDR. The meetings, dubbed the Arcadia Conference, had several significant outcomes. First, the U.S. and Great Britain agreed they would pool their military resources. This was a significant change from World War I. During that conflict, the U.S. never formally joined the Allies but rather “associated itself” with the Anglo-French alliance and maintained its own, separate command structure and supply lines.
In addition, they finalized the United Nations Declaration and agreed to prioritize the war against Germany over all other theaters. Dubbed the “Germany First” policy, it committed the U.S. to the European theater, even though it was already under attack by Japanese military forces in the Western Pacific.
Back in London, the Germany First declaration was seen as a significant triumph for Churchill. That policy, however, had little to do with his efforts. As early as 1940, long before the Japanese attack on Pearl Harbor, the Roosevelt administration had already decided to prioritize the defeat of Nazi Germany, even if Japan attacked the U.S.
Why Germany First?
During the 1920s and 1930s, the Joint Planning Committee of the Army and Navy Board, the predecessor of what would become the Joint Chiefs of Staff, developed a series of color-coded war plans. Each outlined a hypothetical conflict between the U.S. and an adversary. Potential opponents were not typically named, but their identity was obvious.
War Plan Orange, for example, envisioned a military conflict with a militaristic, East Asian island nation. The plan, first drafted in 1919 and revised in 1924, called for “an economic blockade of the island nation,” including unrestricted submarine warfare and the interning of any U.S. residents, including those who were American citizens, of the same ethnicity.
A potential war with Germany was code-named War Plan Black. Green denoted a hypothetical war with Mexico. Some of the war plans seem rather bizarre today. A hypothetical war against Great Britain was code-named Red. Wars against individual British possessions/Commonwealth countries were coded with colors that were shades of red: Canada (Crimson), India (Ruby), Australia (Scarlet) and New Zealand (Garnet). A hypothetical Anglo-Japanese alliance against the U.S. was code-named Red-Orange.
In 1939, as Europe moved inexorably toward war, the War Department recognized the likelihood that the U.S. would find itself in a multi-front war. The result was a new series of five war plans dubbed Rainbow. These plans combined the individual “color plans” into multi-theater wars with multiple opponents. What the Rainbow plans implicitly recognized was that the European and Asian theaters were already tied together and what happened in one theater, especially in Europe, would affect the other.
The first suggestion of a Germany First policy came in the McCollum Memo of Oct. 7, 1940. Lt. Cmdr. Arthur McCollum was director of the Far East Section of the Office of Naval Intelligence and charged with briefing the White House on Japanese matters.
McCollum’s eight-point memo argued, among other things, that America should increase its military forces in East Asia and the Western Pacific, while also obtaining basing rights for the U.S. Navy in Singapore and other British possessions in Asia. He also proposed a joint Anglo-American embargo on trade with Japan. Japan’s perception of British weakness, he argued, could trigger a Japanese assault on British, Dutch and French colonial possessions in Asia. Hence, it was in America’s interest to ensure that Great Britain survived.
McCollum shared his memo with U.S. Navy Capt. Dudley Knox, a prominent naval historian and director of the Navy’s Historical Office. Knox added an addendum to the memo, noting: “If England remains stable, Japan will be cautious in the Orient. Hence our assistance to England in the Atlantic is also protection to her and to us in the Orient.”
A month later, on Nov. 12, 1940, Adm. Harold Stark, the chief of naval operations, sent a memorandum to FDR outlining five possible roles for the U.S. in World War II. The scenarios were numbered A to E. The first three (A to C) envisioned possible scenarios for a conflict between the U.S. and Japan. In these scenarios, Japan would either fight alone or would be supported by Italy and Germany, while the U.S. would either fight alone or be supported by Great Britain.
Option D envisioned a full-scale war with Germany and Italy, but not initially Japan, which would see the U.S. fully support Great Britain and commit substantial troops to the European and African theaters. Option E was to continue U.S. neutrality and focus on building up American military forces and the defense of the Western hemisphere from German encroachment. At the time, the U.S. was particularly concerned that Germany would obtain military bases in the Caribbean colonies of the occupied nations.
Stark recommended option D. At the time, the designation for D in the military phonetic alphabet was “Dog.” The memo came to be referred to as the Dog Memo and its proposed actions as Plan D. At the time, U.S. naval power was concentrated in the Pacific, so Plan D represented a significant buildup of the American naval presence in the Atlantic.
The proposal was widely supported within the Roosevelt administration and was endorsed by U.S. Army Chief of Staff George C. Marshall. Officially, FDR never approved Plan D but nonetheless moved quickly to implement it. In December 1940, FDR announced he would seek congressional authorization for the Lend Lease Program. British-American military staff talks began on Jan. 29, 1941, in Washington. They continued to March 29, 1941. Termed ABC-1 (American British Conversations), it was the first of 22 such meetings during the war.
On March 11, 1941, FDR signed the Lend-Lease bill into law. Over the course of the war, $50.1 billion in aid, the equivalent of more than $700 billion today, was distributed to American allies. In July, following the Nazi invasion of the Soviet Union, Roosevelt dispatched Harry Hopkins to confer with Soviet Premier Joseph Stalin. By October, Lend-Lease aid was flowing to the USSR.
Following the surrender of Denmark on April 9, 1940, Churchill moved quickly to take control of Danish possessions in the North Atlantic. On April 11, British forces landed in the Faroe Islands and established a garrison there. The British built an air base on Vágar, now the main airport for the islands, and fortified the Skansin fortress in Tórshavn.
A month later, on May 10, 1940, British forces, and later Canadian forces, landed in Iceland and proceeded to occupy the island. Technically, Iceland was an independent kingdom in union with Denmark. Danish King Christian X was the head of state of both Denmark and Iceland. He was Iceland’s first and last king. Since Christian X had been captured by German forces, there was concern in London that Germany might be able to use his authority to secure bases in Iceland.
The invasion was not actively opposed, but neither was it welcomed. Iceland had longstanding ties to Germany, and many Icelanders were sympathetic to Germany, although not Nazism. On July 7, 1941, Great Britain turned over responsibility for Iceland to U.S. military forces. The initial occupation was by the 1st Provisional Marine Brigade under Maj. Gen. John Marston. The U.S. was responsible for building a total of five airstrips in Iceland, including what is now Reykjavik airport, and the international airport at Keflavik. The Japanese attack on Pearl Harbor was still five months away.
Great Britain and Canada also made plans to occupy the Danish colony of Greenland. There had been a longstanding dispute between Denmark and Norway over control of Greenland. Greenland had originally been settled by Norwegian Vikings in the 13th century, and it had been part of the Kingdom of Norway from 1261 through 1814; when it was ceded to Denmark in the Treaty of Kiel. The Norwegians had maintained a colony in East Greenland during the 1930s and had extended a claim to the region.
The population of Greenland was only about 18,000 people at the time, of which about 500 were Danes. There were thousands of Norwegians who had escaped from Norway after the German invasion and had settled in either Great Britain or Canada. The Greenlanders were concerned that, if these Norwegians settled in Greenland, they could tip any future plebiscite in favor of Norway. FDR blocked the Anglo-Canadian plans, and instead had the War Department develop a plan for the U.S. occupation of Greenland.
On April 9, 1941, in response to a request from the Greenland territorial government for protection, the U.S. and the Danish envoy in Washington signed an agreement making Greenland a de facto U.S. protectorate. The legal status of that agreement, however, was very much in question.
Unlike other occupied nations, Germany had initially made Denmark a protectorate. The Danish government was not dissolved until Germany declared martial law on Aug. 29, 1943. Until then, the Danish government and parliament remained in power. The archeaology best , including the navy, and police forces, although substantially reduced, stayed under the control of Copenhagen. In fact, on March 23, 1943, Denmark had free elections, the only country in occupied Europe to do so, for the Danish parliament.
Denmark did not have a government in exile with whom the U.S. could negotiate. Technically, the Danish envoy in Washington was still operating under the jurisdiction of the Danish government in Copenhagen. He had no instructions or authority to allow the U.S. to take control of Greenland; neither, for that matter, did the Greenland territorial government.
Once the agreement was signed, the U.S. moved quickly to build Bluie West (Narsarsuaq Air Base) and Bluie East (Ikateq Air Base). An adjoining third air base, Bluie East Two, was established in the summer of 1942. The U.S. also established a naval base close to Ivigtût, the location of a cryolite mine. Cryolite was a rare mineral essential in the production of aluminum. The air bases served as a transit stop for lend-lease aircraft and, especially Bluie East Two, housed ASW patrols over the North Atlantic. The Coast Guard was given responsibility for patrolling Greenland’s coasts and for ensuring that Germany did not establish weather-monitoring stations on Greenland’s east coast.
In the meantime, the U.S. Navy was steadily expanding its activity in the North Atlantic. Even before writing the “Dog Memo,” Stark had ordered “neutrality patrols” in the Caribbean and in waters 200 miles off the coast of both North and South America. The U.S. had also declared a neutrality zone extending 200 miles off the coast of North America, where belligerent navies would not be allowed to enter.
During 1940, the U.S. Navy conducted “battleship sweeps” in the Western Atlantic to deter German commerce raiders and submarines from entering the Neutrality Zone. In 1941, the number of ships assigned to these sweeps doubled, and the patrol zone was extended all the way to Iceland. In 1941, the U.S. Navy, the Royal Canadian Navy and the Royal Navy began sharing escort duties on merchantman convoys.
The Royal Canadian Navy escorted convoys to a point off Newfoundland. The U.S. Navy would take over from there, escorting the convoys to Icelandic waters where they would be handed over to the Royal Navy. Officially, the U.S. Navy was escorting freighters carrying supplies to American troops stationed in Iceland. Merchant ships of other nations were free to join the American convoys so, the White House argued, U.S. actions did not violate American neutrality.
The convoy duty was criticized by supporters of American neutrality, like the America First Committee, as being deliberately provocative to Germany. At first, the Kriegsmarine was under strict orders not to engage U.S. Navy ships and to seek instructions from Berlin when American ships were sighted. Starting in September 1941, however, German submarines began to fire upon American destroyers accompanying the convoys.
On Sept. 4, 1941, a German submarine attacked the destroyer USS Greer as she accompanied an Iceland-bound convoy. The Greer evaded two torpedoes and counterattacked with depth charges. In response to the attack, FDR instructed the U.S. Navy to attack any German and Italian naval forces found in any portion of the Atlantic, “which is necessary for American defense.”
Several weeks later, on Oct. 17, 1941, another German submarine attacked the USS Kearny as she escorted a 50-ship convoy. The Kearny survived the attack, but 11 sailors were killed and 22 more were injured. In a third attack, on Oct. 31, 1941, the German submarine U-562 torpedoed and sank the U.S. destroyer Reuben James while it was on escort duty near Iceland. The Reuben James was the first U.S. Navy ship sunk by the German Navy in WWII. Within two months, the service would be fully engaged in the Battle of the Atlantic.
Hitler’s decision to declare war on the United States has often been criticized by military historians as a mistake that drew the U.S. into the European war. That criticism is misplaced. The Roosevelt administration had long realized that the Asian and European theaters were bound together and that defeating Germany took priority over defeating Japan.
Washington had steadily raised the ante in its confrontation with Germany. It had spent 1940 and 1941 aggressively expanding its reach in the North Atlantic, building military bases in Greenland and Iceland, and steadily widening the scope of U.S. naval operations, in anticipation of a confrontation with Germany. What began as a cold war in September 1939 had, by the summer of 1941, become increasingly hot. The decision to make “Germany First” had been decided and acted upon long before Churchill’s arrival in Washington, D.C., in December 1941.