Prisoner's Hope by David Feintuch
Assigned to Hope Nation while recovering from injuries, Captain Nicholas Seafort is appointed liaison to the wealthy planters of the verdant colony planet. But, reeling from a savage alien attack, the U.N. space flotilla flees homeward, and the colonists seize their moment to rebel. His beloved wife and closest friends gone, Seafort must halt a revolution and rally the ravaged colony against the inhuman invaders. But to save the world, Nicholas Seafort must forsake his vows - and commit an unthinkable, suicidal act of high treason...