The interesting thing about this decision is that they didn’t have to do it. In fact, it would have been far better had they not done it.
This decision has been one of the biggest mysteries of World War II.
Learn more about why Hitler declared war on the United States on this episode of Everything Everywhere Daily.
The United States did everything in its power to stay out of the Second World War.
The war is usually dated as beginning on September 1, 1939, when Germany invaded Poland.
For over two years, the United States kept its distance.
Hitler conquered all of western Europe and was on the outskirts of Moscow in late 1941.
Roosevelt desperately wanted to enter the war. His administration provided support in the form of money and equipment to the British and other allies, but that was the limit of American involvement. They didn’t partake in any combat.
Here I have to zoom out to give an overview of what the relative strengths of the United States and Germany were at the time.
Germany had a population of 86 million people in 1939. The United States had a population of 146 million people. That is a substantial difference of 60 million people.
In 1941, the United States had the largest economy in the world with a GDP of 1.1 trillion dollars. The GDP of Germany was only 412 billion dollars.
The economy of the United States was almost three times larger. Moreover, even before the Americans ramped up production to a wartime economy, they were one of the world’s largest manufacturers of aircraft and automobiles.
To be fair, the US military wasn’t anything to brag about. The number of full-time standing soldiers in the army at the outbreak of war was only around 17,000, with another 220,000 in the various National Guards.
In 1941 the German army had over 3,000,000 men, most of whom had seen combat, and a correspondingly large amount of military equipment.
The only real bright spot in the US military was its navy, which had built up its fleet before the start of the war.
After Pearl Harbor, the hawks in the Roosevelt administration thought they had their casus beli, aka their excuse to go to war.
Here you might be thinking that Hitler had to declare war with the United States due to the Tripartite Pact that Germany signed with Japan and Italy.
This is not true, and the Tripartite Pact was not invoked when Germany declared war. The Tripartite Pact was a defensive treaty that only obligated the other parties to declare war if one of them was attacked.
As Japan was the aggressor against the United States, Germany was under no obligation to declare war.
Moreover, it wasn’t like the Axis Powers were a real alliance in the same way that the Allies were. They never planed anything jointly and they never really worked together.
The Japanese never gave advance notification to the Germans that they were going to launch a surprise attack on the Americans. The Germans suspected that something was going to happen, but they were not privy to information regarding when or where.
So it came as a great surprise to everyone when on December 11, Hitler declared war on the United States. The Americans returned the favor within hours.
The Roosevelt administration, which spent two years wanting to get into the fight, but lacking the excuse to do so, suddenly had it dropped into their lap.
Germany picked an unnecessary fight with a country 50% larger in population, three times larger economically, and moreover, located on the other side of the world where their industrial and manufacturing couldn’t be touched.
Moreover, because Germany never managed to invade Britain, the Americans had a way to attack German economic targets.
Hitler could have just done nothing.
Even if war with the Americans was inevitable, not declaring war immediately might have held it off for a year or two.
That would have given the Germans valuable time to focus their attention and devote all of their resources to their invasion of the Soviet Union.
The North African and Italian theaters would have been postponed or perhaps never have happened, as well as the invasion of Normandy, without the addition of American troops and resources.
There were several strategically dumb things that were done during World War II. The Japanese attack on Pearl Harbor and the German invasion of the Soviet Union were two big ones.
However, at least for those two, each country had some sort of reason for doing what they did, even if the reason turned out to be wrong. The Japanese thought they could take out the Americans in a preemptive attack, and the Germans thought they could overwhelm the Soviets quickly and conquer an enormous swath of land.
With the declaration of war on the Americans, there wasn’t even a pretense for any possible gain. It wasn’t as if he was in any position to try to invade North America.
So why did Hitler do it?
For starters, it isn’t clear that anyone else in the German high command wanted to do this.
When the Japanese ambassador came to see the German foreign minister, Joachim von Ribbentrop, the day after Peral Harbor, von Ribbentrop stalled. He knew that the Japanese wanted Germany to declare war on the Americans, and he knew that this was something that they didn’t need on their plate at that time.
After the war, interviews were conducted with Nazi officials who were present when the decision was made.
It turned out that Hitler made the decision without consulting anyone. It was a totally unilateral decision that surprised many in the upper echelon of the German government.
There were a host of reasons why Hitler took this unnecessary move.
First, he assumed that an American declaration of war was imminent. If there was to be war, then he would rather be the one to initiate it.
Second, he never really thought strategically about the United States. In the early German war planning conducted in 1937, the United States never even came up. He was far too focused on the map of Europe didn’t see the US as a strategic threat.
Third, he viewed the US as weak and decadent. He saw a multiracial democracy, which was the antithesis of everything Hitler stood for. He didn’t see how a country that produced jazz music and motion pictures could possibly be a threat.
Fourth, he overestimated the power of the Japanese. He thought that the Japanese would easily defeat the Americans for the above reasons and that the Americans would probably never even get to Europe.
Fifth, Hitler had some enormous blind spots and some profound ignorance. He never traveled much and was woefully ignorant about the United States. His decisions were made through his prejudices and racial theories, not through any actual data and intelligence.
Finally, Hitler just hated Roosevelt. He was the leader of a bourgeois, decedent country, and he had jews in his cabinet and as friends. He called out Roosevelt in his address to the Reichstag in his declaration of war when he noted:
I will pass over the insulting attacks made by this so-called President against me. That he calls me a gangster is uninteresting. After all, this expression was not coined in Europe but in America, no doubt because such gangsters are lacking here. Apart from this, I cannot be insulted by Roosevelt for I consider him mad just as Wilson was. I don’t need to mention what this man has done for years in the same way against Japan. First, he incites war then falsifies the causes, then odiously wraps himself in a cloak of Christian hypocrisy and slowly but surely leads mankind to war, not without calling God to witness the honesty of his attack-in the approved manner of an old Freemason.
Hitler had some respect for Stalin and Churchill, but he had none for Roosevelt.
So long story short, there really wasn’t a good reason for Hitler to declare war against the United States.
Was war inevitable? Probably. Would delaying the war have changed the outcome? Maybe.
Ultimately, it was ideology trumping strategy, and theory superseding reality, and whenever that happens, reality always wins.