The Issue is that these developments are expensive. Outside of a war you can't keep these secret, the line items are simply too big, the German Empire did have debates over military budgets in the Reichstag. The US and UK would know it, with an open research enviornment they would not be far behind, can just read German scientific journals. When sufficiently scared they will pay out enough to match Germany (Imperial Germany is more capable than the Nazi's, but is not willing to wreck their economy spending on the military like the Nazi's were in peacetime)To have this really happen the way the OP probably wants (not a POW prison break) is close to impossible. However, let me try.
Germany wins WW1 by playing defense. France impales themselves, Russia impales themselves, in 1915 they sow up the Balkans and Great Britain never joins in. By 1916, the Russian army is collapsing, the French army is mutinying, and when Russia completely collapses in 1917 France sues for peace and pays reparations, and does Russia plus giving Germany all of Ukraine, Poland and the Balkans.
Germany avoids the huge amount of debts and financial indemnities of OTL (relatively). By the 1930s, Germany is a Constitutional Monarchy. The USSR is essentially cowed as they bankroll friendly leadership. By 1944, the Germans have long range jet bombers, nukes, and rockets. They keep this secret and a few years later (1950-55) the Brits and Americans overplay their hand over something and the Germans drop the nukes over key British and US naval bases in the Atlantic. The US and Britain do not have the means of serious retaliation. The British sue for peace, the US doesn't.
The Germany navy floats unopposed into Washington DC (Manhattan, Boston, Baltimore, and other large US population centers on the Atlantic are nuked by now.) THe Kreigsmarine bombards DC and an amphibious assault takes place, hoping to surround most of the US's federal government in order to force a peace.
I think the above is at least somewhat plausible, as a German WW1 victory in such a sense leaves Germany with the best university system in the world, less debt (and possibly no Great Depression), a demand for a military buildup (as occupying Europe requires a strong military), and a much better economy and workforce without the Nazis so that Germany will be light years ahead in jet engine, computer, rocket, and nuclear research. The US simply would not have the technology to do much about it (plus, the GDP for military purposes without WW2 would be very small) and the British are simply way too close for comfort.
Not sure what you mean by open society. They still published scientific papers read by the entire world. Newspapers still discussed military appropriations
True, but the US historically spent very little on their military. Until it became really obvious the US had war looming, they kept a standing army smaller than Romania. So, if history is any indication, the US will research things, but not invest the percent of GDP that a European power would in its military.The US and UK can draw on that as well. The US was richer than Germany per capita before the war and growing richer faster and had a larger population that was growing faster, they can pay more. They can also get expertise from other countries on a lot of things and simply buy the expertise from Germany, that was not unusual, they both did that before WWI with weapons
The US started preparing before both WWI and WWII.
When the US gets scared it tends to launch a military buildup, and anyone (besides the UK who already have it) getting the ability to really hurt the US will scare them.
If the US was willing to accept a slower appraoch nukes would be much cheaper, and still come by 1950
The issue is that the coverup would be revealing something is going on weird there. If the top German nuclear scientists stop publishing papers the US and UK would know something fishy is going on there. Same for other subjects, and whatever they wanted would be obvious from the point where they stopped publishingYes, but they were not historically a democracy so that if something was considered of military importance and covered up, that some attempt in covering it up cannot be made successfully. A nuclear bomb program, or rocket program, can have crucial details not released to the public. So, the US and Britain may no that the Germans are trying to build a reactor, they know they are too, and there isn't a second world war where anyone is super concerned to get it out real quick.
It doesn't hurt Germany to have a near monopoly on the science.
If Germany is spending like it is the Cold War, aimed at the US, then the US would spend to match. The US spent based on threats, there was no land based threat to the US so it spent on seapower and coast defenses rather lavishly. So if Germany threatens the US with Bombers and nukes the US will spend in responseTrue, but the US historically spent very little on their military. Until it became really obvious the US had war looming, they kept a standing army smaller than Romania. So, if history is any indication, the US will research things, but not invest the percent of GDP that a European power would in its military.
Again, I think you are presuming the US would be on solid Cold War footing in an arms race. However, the COld War does not exist in this timeline. The US never fought in Europe, and the isolationists would be much stronger and not having the vision to see the necessity to develop weapons to the extent Britain and Germany would.
Two years was the normal minimumBut not long before.
Maybe in Tanks, but the US would be inclined to research jets and nukes for its navy, which was not stinted all that much, or it would not be one of the largest in the world pre WWI. So the US would have a hard time attacking but would be perfectly able to keep Germany over there and not neccesarily need tanks right awayA late crash program in tanks, jets, and nukes is still going to put the US at a disadvantage that they are starting too late and are not going to be drawing upon Britain's science, and a bunch of Europeans who fled Europe.
German immigration to the US in the 20 years before the war was about the same rate as the 20 years after the warI doubt it. The US and Great Britain had many German-born scientists, let alone scientists from the rest of Europe. If Germany wins WW1, they retain funding in their universities and can likely retain and make it attractive for the majority of these men to do research in Germany. I think you underestimate the pressures to immigrate to greener pastures from Germany's WW1 loss that led to a brain drain in Europe.
Simply read up on the Manhattan Project and Britain's nuclear research. There are tons of foreign born people. Take away even half of them and you make a huge difference.
The East German Embassy in Washington is secretly staffed with an entire battalion of military personnel disguised as diplomats, ready to be deployed to seize the city at a single phone call.