YOU MAY think you've seen "Godzilla," the monster flick that launched hundreds of campy sequels. But chances are, you saw "Godzilla: King of the Monsters!"

This American bowdlerization of the original 1954 Japanese version included reshot scenes with Raymond Burr, just so the movie could have an American character. It cut out some 40 minutes of material, completely changed the tone of the ending and dubbed the whole thing in English. It even superimposed Burr into existing scenes, so he would seem to interact with the Japanese characters. Reconstituted as a cheese-ball monster flick, it was a far cry from the initial vision: a sobering cautionary tale about the dangers of nuclear proliferation.

To mark the movie's 50th anniversary, a beautifully restruck print (with the unwieldy title: "Godzilla: The Uncut Japanese Original") has been released for the first time in the United States. Here's an opportunity to see the first -- and a radically different -- film (known as "Gojira") in all its glory. It's in Japanese with English subtitles. The images are crisp. The story is restored. And there's no sign of Raymond Burr.

When a sea monster is discovered in Tokyo Bay, the inhabitants of the city, the media and the government treat it as a threat. But paleontologist Dr. Kyohei Yamane (Takashi Shimura, known to many audiences for his roles in "The Seven Samurai" and "Ikiru") believes the monster should be studied scientifically; it is, after all, a nuclear survivor. But hysteria wins the day. Finally, the destruction of the monster is left to scientist Dr. Daisuke Serizawa (Akihiko Hirata), who has invented a terrible formula (known as an oxygen destroyer) that's even more foreboding than the monster itself. The story also includes a subplot in which Yamane's daughter Emiko (Momoko Kochi) wishes to cut off her arranged marriage to the haunted Dr. Serizawa and take up with Ogata (Akira Takarada).

Given the era, when special effects consisted of low-tech sleight of hand (as opposed to computer-generated imagery), this film is pretty extraordinary. Its miniatures of Tokyo, as well as boats at sea, are amazingly credible. And special effects genius Eiji Tsuburaya devised a convincing 61/2-foot monster suit, framed with wires and bamboo sticks covered in latex, for "Gojira." Performer Haruo Nakajima had to wear a suit that weighed about 220 pounds.

There are some campy elements left in the original. Some of the acting is ham-handed. Many of the big crowd scenes seem amusingly quaint. And it's amusing to hear Dr. Serizawa essaying the English phrase "oxygen destroyer" in the middle of his dire statements about the dangers facing mankind. But despite these moments, there's a surprisingly powerful thrust to this film. And it's instructive to recall the political era in which the movie was made. The atomic bombs of Hiroshima and Nagasaki were still recent memories. And in 1954, the crew of a Japanese fishing trawler had been fatally radiated by the fallout of a nuclear H-bomb test.

Thus, the notion of a sea monster that has been irradiated from atomic tests and is threatening to emerge from the sea is more than a cartoonish cheap thrill. It's a very real metaphor for doomsday. Which is why, when a character in the restored "Godzilla" almost casually mentions that she's a survivor of Nagasaki, it's chilling.

GODZILLA: THE UNCUT JAPANESE ORIGINAL (Unrated, 98 minutes) -- Contains emotionally intense material. In Japanese with subtitles. At the AFI Kennedy Center (starting Friday) and AFI Silver Theatre (May 21).

Emiko (Momoko Kochi), left, and Ogata (Akira Takarada) in the restored "Godzilla."