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I'm not sure how plausible this is, but a post on the Facebook AH group got me thinking.

What would have happened had Germany placed gas warheads on V2-style rockets (or at the very minimum torpedoes), loaded them onto U-boats, drove the U-boats to within launching distance of the US, and then fired? Granted, Hitler had preferred to not use poison gas as a weapon. However, if it's 1944 or something like that and his back is up against the wall...

Deploying poison gas against enemy units may not have made sense as Allies probably had gas masks running around: all that would do would cause the targeted country to retaliate with gas.

An attack on the US coast, however, could serve more as a terror attack to try to get the US out of the war than a typical military operation. The victims would be civilian, so they wouldn't have protection. The US would also have to transport any retaliatory gas munitions over to Europe, which would take a while. Yes, it would have been a war crime, but if you're desperate and are already going to be indicted for the death camps anyway...

I suspect this is impractical, but who knows? I'd assume torpedoes are out as the U-boat would likely be spotted if it got within torpedo range (but if the Germans want US warships back in the Americas instead of fighting somewhere in Europe or the Pacific...)

For this to work, a contagious disease would make sense as the weapon. I'm not sure how well biological warfare had developed by the time though. I can't remember if active agents were used in WWI, and the agents used in the death camps did not have to be contagious in order to do their work (the victims were crowded in rooms and the gas introduced).

A joint operation with the Japanese could be considered as well, with both coasts being attacked at the same time. I wonder if Hitler would allow Japanese access to U-boat technology as they're on the other side of the world and wouldn't be in a position to use it against Germany anyway.

Assume the Manhattan Project proceeds as IOTL.

I wonder if a U-boat could make it up a river without being detected (it would have to be deep obviously). Of course, the commander would need a map of the riverbed which would be tough to come by. Maybe if he got a map of old shipping routes? EDIT: nix the river as the U-boat would be intercepted on the way back out.

What is the range of a rocket capable of launching this warhead? Would a decapitation strike on Washington be in order?
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