Final Justice — Steven L. Hawk

When a hostile race invades Cerbius, a distant planet on the very edge of Alliance territory, Captain Eli Justice fights to defeat them at the point of attack. Meanwhile, his father, General Grant Justice, commander of the Alliance military, implements a plan to defeat the invaders on their home planet. Unfortunately, danger doesn't always come from the outside. On Earth, everything the Alliance has built is threatened by the politics and treachery of newly elected leaders. Working together against common enemies, foreign and domestic, father and son must overcome time, distance, and overwhelming odds to save the Alliance and all of the races that count on them for survival. Welcome to the shout.