I appreciate that question was targeted at Americans but speculation can be fun and I've just finished my second cup of coffee and have nothing better to do until lunch so here is my take on it anyway.
BackgroundIn 1939, Britain faced a growing threat from Nazi Germany under Adolf Hitler. Hitler had already annexed Austria and parts of Czechoslovakia, and his expansionist goals were clear. Poland, situated between Germany and the Soviet Union, was an important target for Hitler. Britain, along with France, wanted to prevent Nazi domination of Europe and maintain the balance of power. This led to the formation of the
Anglo-Polish Military Alliance.
The treaty was not based on the long-standing friendship between Britain and Poland but on strategic necessity. Britain needed to ensure that Poland didn’t fall under German control, as that would have significantly strengthened Hitler's position in Europe.
Why Did Britain Enter the Treaty?- Preventing Nazi Expansion: By 1939, Germany’s expansion was clear. Britain saw Poland as a buffer and key to stopping further German aggression. The treaty promised that Britain would defend Poland if it was attacked by Germany.
- Failure of Appeasement: The policy of appeasement had failed to stop Germany. After the Munich Agreement (1938), it became clear that Hitler’s goals were much broader than Britain had anticipated. The invasion of Czechoslovakia showed Britain that Germany was not content with small territorial gains.
- Maintaining European Stability: Britain’s involvement in the treaty showed its commitment to upholding the post-World War I order and preventing the collapse of Europe into a Nazi-controlled continent. Britain understood that letting Germany take Poland would leave it exposed.
- Strengthening Alliances: Britain’s alliance with Poland was also meant to show France and the Soviet Union that Britain was serious about resisting German expansion. If Britain had failed to act, it risked losing credibility with these allies.
How Did Britain Benefit?- Moral and Political Commitment: By entering into a treaty, Britain was making a clear commitment to stop Germany, and this was something that could not easily be dismissed by Germany or the rest of Europe.
- Prevention of German Dominance: The treaty was Britain’s way of trying to contain Germany without letting it become too strong. If Germany had taken Poland, it would have dominated much of Eastern Europe, further threatening Britain’s security and influence.
- Deterrence: The treaty sent a signal to Germany that Britain would not allow Nazi aggression to go unchecked. While it was a defensive measure, it was a necessary one to prevent the war from being fought on Britain’s shores.
- Coordination with Allies: By formalizing the commitment to Poland, Britain strengthened its alliances, particularly with France, who had a similar pact with Poland. This helped create a stronger front against Germany.
Why Speculation Is Difficult- Logistical and Military Challenges: Even if the U.S. had entered the war earlier, in 1940 its military was not yet ready for a large-scale conflict. The U.S. was still recovering from the Great Depression, and it took time for its military to mobilize.
- Public Opinion and Isolationism: The U.S. had a strong isolationist sentiment after World War I. Most Americans didn’t want to get involved in another European war. President Roosevelt’s efforts to support Britain through the Lend-Lease Act were already controversial, and asking the public to support a full military engagement would have been difficult.
- Germany's Military Advantage: In 1940, Germany’s military was highly effective, with quick victories using blitzkrieg tactics. Even if the U.S. had intervened earlier, it’s unclear if the outcome would have been drastically different, especially considering that Britain was fighting alone in the early stages.
What Might Have Happened?- Support for Britain: If the U.S. had entered the war after the fall of France, Britain would have received immediate military support. This could have sped up the process of preparing for a counter-offensive, though Britain still faced significant challenges defending itself.
- Impact on the War in the Pacific: A focus on Europe would have meant less attention on Japan in the Pacific. However, Japan’s own expansionist policies would likely have drawn the U.S. into conflict with Japan eventually.
- Germany's Strategy: If the U.S. had entered earlier, it might have forced Germany to fight on multiple fronts sooner. However, the German strategy of rapid, aggressive warfare (blitzkrieg) might still have proven effective for a while, especially against unprepared forces.
- Soviet Union's Role: An earlier U.S. entry would have likely changed the timing and nature of U.S. support for the Soviet Union after they were drawn into the war by Germany's invasion in 1941, impacting their ability to resist the German forces. This, in turn, could have affected the post-war relationship between the U.S. and the Soviet Union, potentially altering the course of the Cold War that developed in the following decades.
Conclusion: While it’s intriguing to imagine what could have happened if the U.S. entered the war after the fall of France, it’s unlikely that the outcome would have been vastly different. History unfolded the way it did due to a series of interconnected decisions. The U.S. was not ready for war in 1940, and its entry was primarily forced by events, such as the Pearl Harbour attack in December 1941. The combination of military, political, and public factors meant that earlier involvement was not a realistic possibility.
Lastly, speculating about an alternate history where the U.S. entered earlier will always overlook many of the complexities of the situation. The world was moving toward war, and while different choices could have been made, the timing and course of the war were shaped by forces beyond anyone’s control.
Just my take on the question.
