What happened to the submarines? I know there's quite a few other head-scratchers in this novel but think about it. IIRC the US, USSR, UK and France all have their own fleets of nuclear missile sub's - some of which operate independently from their main navies. Now, some of them could have been destroyed in the initial attack, but there should have been at least a few left over deep underwater or under the ice caps or something. Considering how unprepared the Shongairi were for facing humans, the last thing they'd expect to see would be a nuclear missile streaking up out the ocean to smack into them.
They're fully aware of the world's nuclear capabilities, and nuclear submarines are going to be tightly watched by national governments. The puppies managed to rip the entirety of the Pentagon's database and almost every detail of military deployments, with particular emphasis on nuclear arms. They'll know the general area the subs are in, and they've got to emerge at some point. And sub captains are not going to fire nukes off without authorization or at least a good idea of where a target would be, which would require them to emerge, squirt off a transmission, and pray someone somewhere feeds them a target. That's one of the shitty things about being on a sub; you really have no idea what's going on elsewhere.
So? It's still weird. The book explicitly mentions at least once that the puppies destroyed all the SURFACE ships. Makes a point of not mentioning the subs. You assume there's gonna be a roaring rampage of revenge from a nuke sub at some point... and there isn't. And hell, even the government only has a vague idea of where our subs are, that's the POINT.
What I cannot understand is how the Shongair forces are intelligent enough to utilize surveillance drones and surface-to-orbit stealth reconnaissance platforms and figure out how to mask their approach towards our orbitals, but not intelligent enough, when they initially realize that humans are far more advanced than they previously thought, to consider taking their time in understanding their opponents instead of what they did: gathering a bunch of data that they could barely begin analyzing in one fell swoop, then bombarding our planet once they figured out where the military targets were. Plus, they wouldn't have been strapped for time. They could have poked around on our Internet as much as they wanted without anyone really noticing. And since they were on the far side of the Moon, we probably wouldn't have detected them for months, if not years. Why did they go in with so little intel on their opponents, when they had every opportunity to figure out how humans worked before they started their invasion, instead of during the invasion?
They thought they already knew everything. They figured they had humanity and Earth all figured out. It's the nature of their race to think in terms of only large scale warfare. Once the war is won, all enemies willingly lay down their arm. The whole concept of guerilla warfare and making the enemy hunt each and everyone one of us down is unique to humanity. Still, the main problem was they got carried away by their own arrogance, their own belief and assurance that nothing and no one could possibly stop them. Why wait when you "know" you're going to win?