Here’s Fred Dekker‘s terrific story of Godzilla in a nutshell (a slight edit of the Wikipedia description):
A meteorite collides with an American defense satellite which triggers a nuclear missile to launch towards the Earth. The missile detonates in the middle of the South Pacific, which awakens a giant reptilian creature on the ocean floor. A Japanese fishing vessel is towed to San Francisco for examination after it recently disappeared. Journalist Dana Martin sneaks onto the ship and finds a perfectly preserved trilobite and a burnt survivor whose last words are “Gojira”.
Martin takes the trilobite to paleobiologist and dinosaur expert, Gerald Balinger, who seems skeptical about the fossil’s authenticity. On Oto Island in Tahiti, an American Special Forces squad comes into contact with a giant reptilian monster, who lays waste to nearby villages. Navy Colonel Peter Daxton leads an investigation off the coast of Mexico for a mysteriously sunken Russian submarine. The investigation is secretly being observed by Russian spies and Daxton’s old enemy, Boris Kruschov, who wishes to retrieve the sub’s two nuclear missiles.
Daxton finds a video onboard which reveals that the sub fired one of the missiles on a giant reptilian creature. The missiles are then taken into military custody pending negotiations with Russia. Daxton returns home to San Francisco and his son, Kevin, only to be called back for another mission. Daxton, Kevin, and Balinger are taken to Baja, Mexico where the carcass of a reptile “the size of a house” has washed ashore. Daxton recognizes it as the same creature from the video.
Balinger theorizes that the creature is a dinosaur, however, the military disregard his theories and assume it came from another planet. As Balinger and Kevin watch the military transport the body, Balinger names the creature “Godzilla”, based on an old Japanese myth about a dragon. Off the coast of California, the adult Godzilla surfaces and destroys an oil derrick and a tanker. The dead Baby Godzilla is stored at a warehouse at San Francisco’s Embarcadero for studying purposes.
Balinger becomes alarmed when researchers who came into contact with the body begin suffering from radiation poisoning. Balinger deduces that the Baby is a living atomic reactor with regenerative properties. Since the sea disasters continued even after the Baby’s death, Balinger concludes that the adult Godzilla is coming to the city, but the military disregard his ideas again. Kruschov kidnaps Kevin and demands that Daxton exchange the missiles as ransom. Kevin manages to escape just as Godzilla rises from San Francisco Bay.
The military attack the beast but to no effect, which angers Godzilla into a rampage, destroying the Golden Gate Bridge. Daxton, Balinger, and Martin plan to lure Godzilla out of the city with a recording of the Baby taken from the submarine video and kill it with the Russian missiles. As Daxton flies the helicopter carrying the missiles, Kruschov appears onboard with Kevin and demands the missiles be returned. After a brief fight, the helicopter crashes and Kruschov lands in Godzilla’s hand, where he is incinerated by Godzilla’s atomic breath.
Godzilla finds the warehouse holding its offspring and unleashes a mournful roar after discovering the Baby dead. Balinger and Martin turn on the Baby’s recording at Alcatraz Island, which attracts Godzilla’s attention. Daxton drags the remaining missile onto the Scorpion-78, a high-tech prototype battle helicopter. The co-pilot falls off as the Scorpion-78 lifts off and Kevin takes the co-pilot’s place. As Daxton flies the chopper, Kevin reluctantly fires the missile into Godzilla’s throat, which successfully kills the monster. Kevin falls off the Scorpion-78, but is saved by Godzilla. Kevin weeps as Godzilla takes its last breath.