Germany declares war on united states 1939

Why Germany would do that? Even Hitler's insanity had limits. Germany hadn't any grudge or claimst toward USA in 1939.

But if Hitler would do something so idiotic, generals will overthrown him immediately and new government withdraw declaration of war and explains that Hitler was totally mad.
 
Italy and Japan both step back, way... back. Stalin gets really quiet publicly and has a spectacular drinking party privately. Britain and France stare in wonder and confusion while going "well, we won't be waiting for the help."

Americans on the other hand get quite red-blooded and find themselves having another orgy of Germanophobia. Extra bonus points if Hitler's nuts enough to convince a U-Boat captain to sink a US flagged vessel without warning before the declaration.
 
While clearly a long term Bad Idea... how would it effect the French and British build up?

OTL the US got its industry up to speed supplying the Wallies. Once they entered they war they quite sensibly favored their own troops.

With a 1939 entry it is going to be favoring its own troops who are totally unprepared to fight, while having a more limited industry and less to give/sell to the other Wallies. I am not sure how influential US kit was before the fall of France but it is potentially an interesting change.
 
Neither of them can realistically attack the other country, since there's a whole ocean between them. There might be a naval battle, which Germany will lose, because the US has aircraft carriers. Then a peace treaty will be signed.

It really is utterly pointless.
 
I had this idea from playing heart of iron with germany declaring war on usa with Japan

I'm a fan of the game as well but alternative history is not quite as simple as Hearts of Iron. You seem to have disregarded 6 years of rising tensions in Europe; Anschluss, Munich, etc. with your assumption that the invasion of Poland was the be-all and end-all of WW2.
 
So why in the world declare war on the US when Hitler's only problem with the US was precisely that it might aid France and the UK in case they went to war with Germany?

Hardly. There was also that thing about the US being "the home of international Jewry".
 
Hardly. There was also that thing about the US being "the home of international Jewry".

One has to distinguish between Hitler's mixed but basically low opinion of the US (strong industrially but racially mongrelized, under Jewish influence, etc.) and any cause for immediate war. Hitler did not want war with either Great Britain or the United States. War with Great Britain would come only if the British sought to block Germany's expansion on the Continent. War with the US would come only if the US sought to back Great Britain in such a war. In the OP here, there is no war with Great Britain, and there isn't even any continental expansion by Germany in 1939--it does not attack Poland or France (let alone the USSR which it doesn't even border). Yet somehow Hitler declares war on America and only on America! This makes absolutely no sense.

The truth is that Hitler was anything but obsessed with the United States during the 1930's. He just didn't think it could play much of a role in European affairs, given the strength of isolationism.
 
While clearly a long term Bad Idea... how would it effect the French and British build up?

OTL the US got its industry up to speed supplying the Wallies. Once they entered they war they quite sensibly favored their own troops.

With a 1939 entry it is going to be favoring its own troops who are totally unprepared to fight, while having a more limited industry and less to give/sell to the other Wallies. I am not sure how influential US kit was before the fall of France but it is potentially an interesting change.
A whole lot of P-40s would show up in Europe. More German casualties earlier would shorten the war.
 

DougM

Donor
Assuming some logical POD, say the US opens its doors to all German Jews and moves to actively protect them as best as possible such as embargo of Germany and locking down all German money on an international basis to use to recompensate the displaced Jews. Then you have the following

-France and England DONT go to war as Poland is not invaded (at least that seams the premise of the OP)
-The US still has plenty of time to build up its Army and Airforce as it is not like Germany can get to it,
-The US will radically overbuild its military as it is a way of getting out of the Depression as it puts young men to work in the military and it puts older people to work building equipment
-The US Navy will blockade Germany and sink anything from battle ships to rubber duckies that say “made in Germany “. This will be worse for Germany then England because the US not being an island is not as worried about protecting shipping in this TL as England was
-A LOT of shipping on English and French ships as Germany won’t dare attack them for fear of forcing England and France into war.
-The earlier US build up will pretty much put the kabash on Japan attacking Peril as the US will be on a military footing sooner and have a bigger Army and Navy then OTL.
-The fear of war plus support for the US and pressure from the US (in various combinations) will result in Germany losing almost all foreign trade and financial support. This ultimately will bankrupt Germany
-No Loot from invaded countries means Germany will collapse economically sooner the OTL.
-The US Navy will sink the Bismarck and pretty much the rest of the German Navy.
-Other then some navel battles the war will mostly be a non starter.
-Ultimately Germany will collapse with little to no fighting.

One outside possibility is that Germany does something even more insane and invades Poland also. In this case you will see US troops and Aircraft in Europe and Africa sooner. So the US will learn the lessons along with England and France, Depending on the Date Germany declairs war it may be soon enough for the US to mobilize and send troops to France, odds are this doesn’t stop the Fall of France but it could.
This will also result in the German subs being sunk faster as the US will be actively hunting them from day one.

So in general Germany will fall sooner. Ironically I think Germany falls sooner with Just the US as it won’t have any captured territory to sustain it. But either way I think the way ends a bit Sooner.
 
Assuming some logical POD, say the US opens its doors to all German Jews and moves to actively protect them as best as possible such as embargo of Germany and locking down all German money on an international basis to use to recompensate the displaced Jews.

The first part, though very unlikely (even modest attempts to take in more refugees drew strong political opposition) would actually have been welcomed by Hitler in 1939. As for the second, there is not a chance of it.

When something extremely implausible is posited, you don't make it plausible by saying it was provoked by something equally implausible...
 
Nothing would happen.

Germany doesn't have the navy to take the war effectively to the US. There is absolutely no way the Germany of 1939, surrounded by would-be enemies, can carry a war across the Atlantic against the US.

In any case, if for some ASB reason Hitler abandoned his lebansraum plans and decided to go all out against the US and built up his navy, The RN would surely step in and swat them even before they reached the USN?
 
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