Starmada: Hammer and Claw

(From the http://mj12games.com description)

The claw, bloodied, represents war. On seven occasions the Grumm have encountered those that are not Grumm, and three times they have parted in peace. Four times Grumm have died, and those who mourned have called for the Assemblage, claws unsheathed. Before, the enemy was excised, without pity or hate. The Grumm are the children of war, but they take no joy from killing. It is a tool, applied as all others are applied, to secure tomorrow. Those who threatened the future died, whether in their ships or on the ground, until they posed no threat. They were reduced so that, as under the Law, the Grumm need not fear them for the span of ten thousand litters. Hammer & Claw: The Grumm Wars Source book is a supplement for the Starmada game, detailing a universe in which Mankind’s first contact did not go well...

The Wars are an ongoing conflict between Earth's space faring nations and the Grumm, bent on exterminating what they perceive as a threat to their very existence. Hostilities are driven, as with most wars, by greed, misunderstanding, and fear, in equal measure. Can Earth's superpowers, wary and distrustful of each other for more than 300 years, unite in the face of a common enemy? Or has humanity already doomed itself to annihilation?

In addition to extensive background material describing the Grumm Wars universe, this book contains thirty-five new starship designs representing the alien Grumm, the nomadic Boers, and Terra’s three space faring powers: the Union of European States, Daitoua Kyoueiken, and Pan-Atlantic Commonwealth. Also included are several scenarios, plus all of the supplemental rules necessary to fight out the Grumm Wars, including brand-new options such as shipboard combat and dual-mode weapons.