The Stars at War

Crusade: Neither side in the Human-Orion war was strong enough to defeat the other, so it fizzled into an uneasy peace filled with hatred and mistrust on both sides. Then a ship appeared from the dim mists of half-forgotten history, and fired on the Orion sentry ship, igniting the fires of interstellar war anew, in a quest to free Holy Mother Terra.
In Death Ground: The human race and two other star traveling races had warred with each other in the past, but now all three are at peace-a peace which is shattered by the discovery of a fourth race, the "Bugs." The newcomers are mind-numbingly alien in their thought processes, have overwhelming numbers, and regard all other species as fit only to be food animals. There is no hope for peace with the invaders, and the galaxy explodes with a battle to the death. Kill-or be eaten!