Examining World History: Why Did Adolf Hitler Declare War on the U.S. in December 1941?

The answer is simple. Adolf Hitler took a huge gamble….and lost.

For the first two years of the Second World War, Hitler’s policy toward the U.S. was to hope that isolationism, anti-British sentiment in certain segments of the American public, and internal divisions would keep President Franklin D. Roosevelt too busy to enter the conflict before he had conquered the Soviet Union. He may have believed that FDR, who was clearly a supporter of Great Britain, would lose the 1940 Presidential election to a candidate who would be more accommodating to German hegemony in Europe.

Hitler was none too thrilled when the Roosevelt Administration and a bipartisan Congress passed the Lend-Lease Act and sent the U.S. Navy to escort convoys as far as Iceland. But even when this led to an undeclared naval war in the Atlantic, the German dictator still held off from declaring war on America.

Why? Partly because Hitler suspected that it would take the Americans several years to rebuild its military forces from their relatively humble size. The U.S. Army in 1940 only had 174,000 men under arms, which ranked 24th in the world, right below puny Romania. The Navy, FDR’s branch of choice, was in better shape than the Army, but it was still no two-ocean juggernaut.

You have to remember, too, that at the time of Pearl Harbor (December 7, 1941), Hitler’s armies had conquered most of Western Europe and held vast areas of Russia. Yes, Operation Barbarossa had failed to capture all of its objectives before Generals Rain, Mud, and Winter came in on the Soviet Union’s side. And yes, the pesky Ivans had counterattacked the heretofore unbeaten Wehrmacht in front of Moscow and pushed German forces back a bit. But if Hitler could get his soldiers to hold on and wait until the spring and summer campaigning season, Germany could withstand this temporary setback.

So when news reached Berlin that Japan had carried out a devastating attack on the U.S. Navy, Hitler was faced with two choices: stay neutral, or declare war.

The best option, from an objective point of view, was to remain officially neutral in the fight between Japan and the Anglo-American alliance. The Tripartite Pact of September 1940 did not bind any of the signatory powers to a mutual defense stance if one was the aggressor in any conflict involving a third power which was not an official belligerent. This is, perhaps, one reason why Japan did not attack Russia in the summer of 1941; Hitler, not Soviet dictator Josef Stalin, was the invader. (Another reason: Japan was soundly trounced in a series of skirmishes in Mongolia in 1939 by Soviet forces led by future Marshal G.K. Zhukov; the Japanese generals didn’t want a second trouncing.)

Neutrality vis a vis the Pacific War also would have reflected Germany’s hope that the U.S. would shift its focus from the Atlantic to the Asia-Pacific Theater. This seems like a logical assumption: if Germany refused to react to FDR’s provocative moves in the North Atlantic and the Bases-for-Destroyers deal with Britain, American public opinion would demand that all of America’s might be aimed at Tokyo, not Berlin.

Now, although Hitler remembered all too well that America’s late entry into World War I had contributed greatly to Imperial Germany’s defeat in 1918, he also felt contempt for a country controlled by a “mongrel race” and “Jewish plutocrats.” And like the military rulers of Japan, he looked down on Americans as a “nation of shopkeepers,” too softened by the ways of democracy and its racial mix to be much of a challenge for his Aryan warrior-nation.

Add to this the results of the Pearl Harbor attack and the reports of early Japanese victories against British and American forces in the Pacific…..

In addition, Hitler consulted with none of his close associates before making the decision to go to war with the U.S. As historian Stephen E. Ambrose once wrote, “it was the loneliest decision” that Hitler made during World War II.

And Ambrose goes on to add, “It was also the looniest.”