Honestly, the first thing I always think of when this story comes up is how I found out about it - a coworker who suggested I read it and basically said this was a desirable thing to do.
The fact we worked as park rangers at the Statue of Liberty just makes it more memorable.
Sounds like he was some kind of white nationalist science fiction fan.
B Munro did a
write-up of what the Unparalleled Invasion world might look like a few decades in the future.
Something worth remembering about Jack London is that he wrote multiple "future history" type stories of which "Unparallel Invasion" was only one. Some have science fiction elements but others have very little mention of futuristic technology and focus solely on political and social changes. London was a socialist despite his white nationalist and social Darwinist inclinations, as can be seen in his
Iron Heel which is one of the first dystopian novels ever published, depicting a rising socialist movement in the United States being crushed by an authoritarian oligarchy. While socialism eventually triumphs centuries later, the protagonists of the novel perish in a doomed resistance against the tyrannical "Iron Heel". The novel reads like an inverted Atlas Shrugged at times with a didactic message, dystopian setting, a female protagonist, and a resistance effort against the government. The narrator's husband, Ernest Everhard, could easily be a Randian hero if given a different ideology. The
Iron Heel almost certainly influenced the neo-Nazi novel
Turner Diaries which are both written as the recently discovered manuscript of a deceased (and martyred) hero of the revolution. The "Unparalleled Invasion" no doubt influenced that vile work as well, which concludes with nuclear and biological warfare being used to depopulate much of Eurasia in response to a rising China.
London's other FH stories can be seen almost as various "alternate futures" of the one envisioned in the Iron Heel:
The
Scarlet Plague depicts a post-apocalyptic future where humanity has reverted to Stone Age hunter-gatherer conditions decades after a lethal pandemic annihilated 99.99%+ of the world's population. The plague itself occurs in the then future year of 2013 when the world is under the control of a plutocratic "International Board of Magnates" who have the power to designate US Presidents and regard the working-class as little more than slaves and savages. It is a catastrophic potential future of humanity with the lethal plagues of the "Unparalleled Invasion" and the oligarchy in the Iron Heel uniting to not merely retard but utterly destroy humanity's hopes of a socialist future. This novel reinforces certain arguments I've read that the "Unparalleled Invasion" is not a celebration of genocide but rather a satire of Western imperialism and technology.
A
Curious Fragment is arguably set in the same universe as the Iron Heel though here the oligarchy continues centuries after it is supposed to have fallen in the main Iron Heel timeline.
Goliah shares the wunderwaffe aspect of Unparalleled Invasion but here it is wielded by its socialist inventor to bring about a revolution centuries ahead of time. Interestingly, the wonder city of Asgard is mentioned both here and the Iron Heel but with the difference that here it is built by a socialist government while in the Iron Heel it is constructed by the oligarchs as a way to consume surplus resources.
Enemy of All the World is yet another superweapon future history story and the spiritual antithesis of Goliah with the inventor being an embittered maniac who uses his weapon not just to slaughter people but deliberately cause wars. The story has certain uncanny coincidences such as the protagonist blowing up multiple battleships which causes a German-American War in 1939 and him being executed on December 4th 1941. This work clearly satirizes militarism etc., reinforcing the interpretation of the "Unparalleled Invasion" as satire.