The following books are recommended by 3rd Brigade OIC. All are genre and fiction – but most still apply to leadership and military concepts. They will be organized by topics I feel the books best address. 

Leadership: 
All of the Honor Harrington Series, by David Weber. 
The Way of Kings – Brandon Sanderson 

Dealing with unintended consequences: 
Speaker for the Dead – Orson Scott Card (Book in the series of Ender’s Game)  

Adaptability and Strategy: 
Destroyermen series – Taylor Anderson

General philosophy: 
Chapterhouse (final book in the Dune series written by Frank Herbert) 

Being overly stubborn when you have a good crew to rely on: 
The Longmire series by Craig Johnson