Reddit reviews Protector (Known Space)

Brennan-Monster lived to see himself get blamed for any unexplained abductions or course changes in the Belt, as well as random abductions on Earth.

> It's a logical deduction

Also, the events of Protector have already happened. Protector happens before Ringworld, but was published after Ringworld. Some spoilers within.

The Pak Protector species in Larry Niven's novel Protector and the later Ringworld novels.
The Pak care for nothing except ensuring that their bloodline will survive.

Some of my favorites:

• Noir - K.W. Jeter
  
• Macroscope - Piers Anthony
  
• Armor - John Steakley
  
• Protector - Larry Niven
  
• I Robot - Isaac Asimov
  
• Neuromancer - William Gibson
  
• Do Androids Dream of Electric Sheep? - Philip K. Dick
  
• The Fall of Reach (Halo) - Eric Nylund
  
• Stranger in a Strange Land - Robert Heinlein
  
• Cachalot - Alan Dean Foster
  
• Islands in the Net - Bruce Sterling
  
• Ender's Game - Orson Scott Card
  
• Reality Dysfunction - Peter F. Hamilton
  
  I tried to get as many different authors as possible in there. Many of those authors have plenty of really good books you shouldn't miss.

If I didn't know better, I'd accuse you of cribbing off my universe. ;)

Okay, so the first thing you need to do is go read Protector by Larry Niven. This is the book actual military strategists study when considering relativistic combat. (Also it's a good book.) It is non-optional for any relativistic interactions. Seriously. Just go read it now.

Now next up, people claiming that Charles is going to have a disadvantage: you are so totally wrong. Charles is going to have a massive advantage. One, they know the area and territory better. Two, how the hell are you going to counter the unexpected? Unpredictability is a HUGE advantage. If Bob's rigged to fight against slow rail gun ships and runs into Charles' speedy lasers, Bob is so totally screwed. Follow?

Bob can't counter Charles in a reliable fashion, so Bob is going to eat some heavy losses. The lack of unified objectives will hamper Charles' effectiveness, but it'll still be akin to death by a thousand papercuts. Just cruising along and BAM, some loon decided to go for one of the colony ships because they looked like a tasty target.

It is going to be a long, drawn out mess either way. Charles' forces are going to be a natural asymmetric force, which makes them thousands of times harder to fight. If they're the same species or can pass for it, you can expect Charles to also engage in sabotage and possibly turning folks from Bob either for use as spies as saboteurs.

A few other options (and these might have been mentioned in previous comments):

Clarke's Rama series (although the first two of the four, in my opinion, are the best).

Niven's Ringworld series -- Note: there is a great variety in the quality of these books-- some are great, some are not. The first one, Ringworld, is superb and definitely an anchor of the "Big Dumb Object" type of books. Protector is also great!

Peter Hamilton's Pandora's Star -- followed by Judas Unchained and the Void Trilogy ! Great world-building!

Greg Bear's Eon series

By the same author of Red Mars, pickup Icehenge -- a shorter read but definitely full of Kim Stanley Robinson's world-building depth.