Colonization

In the Worldwar tetralogy, set against the explosive backdrop of World War II, master of alternate history Harry Turtledove wove a saga of world powers locked in conflict against a deadly enemy from the stars. Now, with Colonization: Second Contact, Turtledove expands his magnificent epic into the volatile 1960s - when humanity must face its greatest challenge: alien colonization of planet Earth.
During the Worldwar, Washington, D.C., Tokyo, and dozens of other cities perished in the radioactive holocaust of nuclear battle. Twenty years later, a fitful peace reigned over the continents. Though Himmler controlled Germany and France, Molotov ruled Russia, and President Earl Warren tenuously governed the United States, the invaders lorded over most of the world - coexisting in an uneasy balance with humans. As both the alien and human races experience the rampant social turmoil of the sixties, they are fatefully influenced by the tremendous upheavals - and by each other.
Then amidst this strife comes a new phase of the alien invasion... the arrival of the colonization fleet - an enemy that seeks to sweep humankind aside on a global scale. The fleet's terrible goal is to colonize and seize control of every man, woman, and child on Earth. Yet as governments feverishly develop weaponry, a terrible truth emerges: This war will be fought not only on the the ground but in the vacuum of space. The United States must summon all its technological genius - or face destruction.