Anything You Can Do… : Post-Apocalyptic Sci-Fi Novel

There has been a nuclear war on Earth, and from the ashes rose a new society with a world government run from the capital city built on Manhattan Island after Manhattan was obliterated by a "sun-bomb." Far out in space, a four-eyed, eight-armed alien known only as "the Nipe" is looking for someplace to set down and repair his damaged, gradually failing spaceship. Nipe crashes on earth and begins to wreak carnage and death as it tries to survive and to find a way off the planet. No one survives contact with the alien and no one can determine the reasons for its actions. The only solution appears to be to develop an enhanced human to confront and defeat the alien.