JohnBrownsBussy2 [she/her, they/them]

Delta Green has some elements of this, with an occult faction of the SS (the Sonderkommando Hexen, or Karotechia in universe) communing with the Deep Ones, making use of reanimated corpses and making a last-ditch effort to destroy the world by summoning Azathoth. There’s no campaign per say, but the handler’s guide has timeline that outlines potential scenarios. I think World War Cthulhu and Acthung! Chtulhu have similar campaigns.