Strangers from the Sky

Summary
From the back cover: In the twenty-first century: United at last after countless years of warfare, humanity turns towards the stars. But when an alien spacecraft crash-lands in the South Pacific bearing visitors from another world - the Vulcans - Earth must decide whether to extend the hand of friendship, or the fist of war...

While in the distant future, horrible dreams torment Admiral James T. Kirk, dreams promoted by his reading of "Strangers from the Sky", a book about the historic first contact. Dreams of an alternate reality where he somehow changed the course of history - and destroyed the Federation before it began!