A Desert Called Peace by Tom Kratman

Five centuries after settlement, Terra Nova, Earth's sole interstellar colony, has ended up remarkably like 21st century Earth - socially, culturally and politically.  When Salafi madmen bent on a new jihad kill Patrick Hennessey's wife and children in a cowardly attack, they create an enemy that will show even less mercy than they do. 

A retired military officer from a wealthy family background, Hennessy raises a mercenary army from the decrepit remains of a military in a failing state and wages a personal crusade on terrorists, their allies and supporters, wherever they are and whoever they might be.  They rapidly prove themselves to be more ruthless (using torture, assassination and intimidation) and more effective than any other country, despite their limited resources and relatively small numbers.

A Desert Called Peace, like many of Kratman's stories, is primarily a dystopian novel based on current events.  Closely paralleling the historical aftermath of the World Trade Center attacks, Kratman explores the nature of war and terrorism as well as recent events and provides, through Hennessy's actions a guide to how he thinks the war on terror ought to have been fought, and where those efforts have come up short in the real world.

The book, the first in a growing series, can be found here for free.  If you enjoy it, please support the author and buy the rest - Carnifex, The Lotus Eaters, and The Amazon Legion.