Name: Defenders
ISBN: 9780316217767

Will McIntosh

A new epic of alien invasion and human resistance by Hugo Award-winning author Will McIntosh. Our Darkest Hour. Our Only Hope. The invaders came to claim earth as their own, overwhelming us with superior weapons and the ability to read our minds like open books. Our only chance for survival was to engineer a new race of perfect soldiers to combat them. Seventeen feet tall, knowing and loving nothing but war, their minds closed to the aliens. But these saviors could never be our servants. And what is done cannot be undone.

Defenders

Janice Hopper

Earth is being invaded by the alien Luyten. We don't know why. They came in a generation ship from a long ways away. The Luyten don't believe the humans can coexist with them, so they come in guns-ablazing. Moreover, the Luyten can read the minds of any human within 8 miles of them. This makes it tricky for the humans to plan anything in secret, obviously. So humanity is getting its collective butt kicked. They need a weapon. They need a mind the Luyten can't read.

So they create the Defenders. They're a sort of giant super-soldier, 15 feet tall, with 3 legs, no serotonin to speak of in their brains. Apparently the presence of serotonin is what enables the Luyten to read minds. It also renders the Defenders a bit... sociopathic. They're very effective against the Luyten, and humanity starts winning, with the Luyten driven back and eventually forced to surrender.

But when the war is over, what do you do with highly aggressive, giant, sociopathic soldiers with nothing to fight? They wanted Australia, so they got Australia. And they took the Luyten that were still alive with them as slaves.

But that wasn't going to be the end of the fighting, as anyone with half a brain could see.
I'd had this book on my TBR pile for a long time, because the idea of what you do with giant sentient weapons after the war was over was interesting to me. I'm sad to say I'm pretty disappointed with how this one played out. It was all just a bit too simplistic, focusing on the big battles rather than the philosophical implications of sentient weapons. 

I confess I like enough hard SF in my novels that I don't get distracted by the "Wait, but how could they do that??? That doesn't make sense" questions. The author had to deploy too much handwavium to make his plot work. At the beginning of the story, we're told that there'd been so many losses that you went into the army when you turned 16 whether you were male or female. The human race lost something like 3 billion people as well as infrastructure to the Luyten. But they still had the resources to build multiple huge underground facilities to create (the process is hand-waved away) the Defenders. And the internet never went down, LOL. The book is full of things like that, and that annoyed me.

The characters were fairly wooden. You never really get invested in them. And one of the most sympathetic characters was an alien.
 
The end was unconvincing. Apparently the origin of the novel was a short story, and I'd bet it read much better.

So maybe 2.5 stars out of 5. Big ideas, disappointing execution, and almost a complete miss on what could have been an interesting discussion.