Dragon by Clive Cussler

Japan, 1945: Two U.S. bombers take off with atomic bombs. Only one gets through.
The Pacific, 1993: A Japanese cargo ship bound for the United States is instantly, thunderously vaporized, taking with it a Norwegian vessel. Japanese fanatics have developed a chilling plan to devastate and destroy the Western powers. From the ocean depths to the discovery of cache of lost Nazi loot,