Without the politics, the re-cut dubbed story of the dinosaur-like creature with radioactive breath, was an anodyne monster-on-the-loose picture which none the less added the name "Godzilla" to the lexicon of popular culture.
Such has been the success of the spin-offs, including more than 20 sequels from the Japanese studio that invented him, a major computer-generated Hollywood movie version seven years ago and assorted cartoons, that even fans may not know there was ever a serious point to the plot.
But now British audiences are to get their first opportunity to see the complete Japanese version of the film deemed politically unacceptable for ordinary Americans - and hence the rest of the world - half a century ago.
Next month, in the wake of the 60th anniversary commemorations of the first atomic bomb being dropped on Hiroshima, the British Film Institute (BFI) is releasing this landmark in science fiction movie-making in its original form.
Margaret Deriaz, the BFI's head of film distribution, said the film had proved an important cinematic phenomenon. "Along with King Kong, Godzilla is one of the most celebrated movie monsters of all time, yet hardly anyone in this country has seen the original that sparked the phenomenon," she said.
"That's why it's fascinating to go back to the original and see how it all really started as opposed to the terrible distortion of the film that was caused by the release of the butchered American version.
"When this original version was finally shown in America last year, people flocked to see it. They said it was an expression of nuclear anxiety to rank with Dr Strangelove [Stanley Kubrick's 1964 black comedy starring Peter Sellers] and Hiroshima Mon Amour [directed by Alain Resnais in 1959]."
When Godzilla - or Gojira in Japanese - was made by the Toho studio in 1954, it was a last-minute substitute for another project that had fallen through.
Directed by Ishiro Honda, whose own experience of the bombing of Tokyo encouraged him to translate the horrors of war into film, its star was undoubtedly the monster Godzilla.
Godzilla was realised by Eiki Tsuburaya, a special effects expert who had spent the war making propaganda films including a recreation of the bombing of Pearl Harbour using miniatures that were so real the Americans were convinced it was documentary footage.
Transformed and provoked by mankind's nuclear bomb tests on the floor of the sea, Godzilla goes on the rampage, creating scenes of devastation that clearly recall wartime Japan. Only a machine invented by the scientist, Dr Daisuke Serizawa, can kill him, but the doctor worries about his invention falling into the wrong hands.
Faced with hundreds of people dying from radiation, he relents. The film concludes, however, with a warning that more monsters could be provoked unless nuclear testing is ended.
The whole project was Japan's first foray into big budget science fiction and cost 10 times the budget of the average Japanese film, and twice as much as the same studio's The Seven Samurai which was also released that year.
Only a decade after Japan surrendered to the Allies after atomic bombs were dropped on Hiroshima and Nagasaki, the effects of nuclear attack and radiation were still a sensitive subject for the country's citizens. " The bombings created a deep collective fear," Ms Deriaz said.
Those concerns were compounded when America, followed by the Russians, first exploded the newly-developed hydrogen bomb in 1952. And two years later there was public outcry in Japan when American H-bomb tests on Bikini Atoll, in the Marshall Islands, caused radiation sickness among the crew of a Japanese tuna boat, Lucky Dragon.
Nothing was more likely to grab Japanese public attention than a story in which bomb tests awaken a long-dormant, 30-storey high, monster with white-hot radioactive breath.
"With its images of panic and mass destruction - including spectacular nightly attacks on Tokyo - and its references to nuclear contamination, black rain, bomb shelters and the incineration of Nagasaki, Godzilla struck a chord of terror with Japanese audiences traumatised by recent history and still living with the fear of radiation poisoning," Ms Deriaz said.
Having cost 60m yen (about $900,000 in the rates of the time), it took 152m yen from 9.6 million viewers at the Japanese box office and is now widely regarded as one of Japan's most important feature films.
Although it owed much to the 1933 thriller King Kong, which had been re-released in Japan after the war, and to Beast from 20,000 Fathoms, a 1953 film about a pre-historic sea giant written by Ray Bradbury, Godzilla was one of a raft of Japanese films to address the atomic age.
Others include Shohei Imamura's 1988 movie, Black Rain, or Akira Kurosawa's Record of a Living Being, released the same year as Godzilla, or later Kurosawa work such as Rhapsody in August in 1991, all analysed in books such as Hibakusha Cinema: Hiroshima, Nagasaki and the Nuclear Image in Japanese Film" edited by Mick Broderick.
It has been argued that the bombs have also influenced Anime (Japanese animation) and Manga (the Japanese equivalent of the American comic book), most obviously in Barefoot Gen, the multi-volume comic written by artist Keiji Nakazawa who was seven when his home city of Hiroshima was hit.
The effect of the bombs was, perhaps, particularly damaging to the Japanese psyche, says Terry Charman, a historian at the Imperial War Museum, because of the strong internal propaganda about Japanese victories in the war. " It was a terrific shock," he said. "The people of Japan were being fed a diet of mis-information. The emperor in his broadcasts doesn't say, 'We've been horrendously defeated,' he says, 'The war isn't necessarily going in Japan's favour.' There is a feeling in Japan that they were cheated out of victory, that the atomic bomb was a dirty way of warfare."
Whatever the rights or wrongs, the anger that informs the original Godzilla would have made it difficult to sell without editing in America, according to the BFI's David Sin.
"It would have been fairly unpalatable in America. You can't miss the message. It's not a sub-text, it's very much the subject of the film," he said. "But the other reason they cut it was to insert an American presence in the film and make it work better for an American audience. Foreign language films were very much art films in Fifties America."
So the nuclear message was removed and the actor Raymond Burr was introduced as a news-wire reporter commenting on the action. Although this version received none of the critical acclaim now poured upon the original, it did nothing to stop the franchise.
Toho made more than 20 sequels, although few have the sophistication of the original's plot, often descending into fights between Godzilla and rival terrors. The studio said that Final Wars was the last in the series when it was released in Japan and America last year but has now produced another.
Besides, Godzilla has taken breaks before and returned. In the mid-Seventies he lay dormant when cinema audiences fell, leaving the Godzilla story in the hands of Hanna-Barbera productions who produced an animated Saturday morning cartoon in 1978 which had repeated airings throughout the 1980s and is still periodically broadcast on satellite.
Margaret Deriaz said the British Film Institute began thinking of releasing the original version in the UK, in cinemas followed by DVD next February, partly because of the 60th anniversary of the Hiroshima and Nagasaki bombings.
"Godzilla is a film that is popularly known in its American released version but the Japanese original version isn't known in this country at all, " she said.
"BFI distribution activity is a lot to do with celebrating classic cinema and rediscovering unjustly forgotten or neglected or misrepresented films in their original, uncut versions, often with restored prints. We give people a chance to understand what these titles were about and appreciate them in their proper cultural context.
"Seen in context, Godzilla is not really a futuristic sci-fi fantasy, it's a very real reflection of contemporary terror drawn from contemporary events."
Asked whether the film's special effects stand up to scrutiny after half a century, Ms Deriaz paused. The working methods of the time were, after all, less than ideal.
Godzilla sequences had to be shot at a higher frame rate than the normal 24 frames per second so that he lumbered realistically when played at normal speed. This required extra bright lighting that frequently made the two actors who took it in turns to don the Godzilla suit faint.
But Ms Deriaz said the results were "much less cheesy" than could be expected. "You might be tempted to laugh at what, by today's standards, are primitive special effects, but very soon this haunting, elegiac mood takes hold of it and you can't just laugh. It is ultimately quite sobering.
"The message is driven home that it's man's own insatiable lusts that have brought this about. It's on a par with the way we're all being warned about global warming and looming environmental disaster today."
Godzilla opens at the Curzon Soho and the ICA, London, on 14 October and then at venues nationwide
The many lives of a giant lizard
'Godzilla' - the Hollywood version
Roland Emmerich's post-Jurassic Park remake of 1998 had special effects far better than any that had gone before, but fans were deeply disappointed by its conventional approach. But the Hiroshima allegory has vanished; this Godzilla has been created by (get this) French nuclear testing, and he runs amok in New York, not Tokyo. Without atomic plasma breath (though he does apparently have one of the worst cases of dog-breath ever encountered), this was really a remake of The Beast from 20,000 Fathoms. On the plus side, Jean Reno - replacing Gerard Depardieu as the acceptable face of Frenchness - is very funny as an enigmatic giant-lizard expert.
Godzilla - the kids' cartoon
The Hanna-Barbera cartoon series started in 1978, at a time when HB were insisting on saddling every character with a "cute" juvenile sidekick (Scrappy-Doo, Scooby's murderable nephew came the following year), hence Godzookie, Godzilla's annoying little lizard pal. In this version, too, Godzilla was not simply benevolent, but positively biddable, thanks to a special radio communicator. The standard of animation was not high, with Godzilla shifting size radically at the drop of a hat. Even among devotees of kitsch, the series is remembered with little affection.
'Bambi Meets Godzilla'
A timeless comedy classic, which should be used as a teaching aid in every film school in the world, to inculcate the virtues of brevity and simplicity. The plot is easy to recount: after the opening credits, Bambi skips about, grazing on grass. A giant lizard's foot appears above him, and descends, squashing him flat. Cue closing credits. The Canadian animator Marv Newland made it in 1968, the year before Terry Gilliam created the giant foot for the opening credit sequence of Monty Python's Flying Circus. A 1999 sequel, Son of Bambi Meets Godzilla, was produced independently.
Godzilla meets Barney
Starting in 1991, the children's cartoon series Rugrats, created by Gabor Csupo and Arlene Klasky, detailed the rich inner life of a group of pre-school infants: a leitmotiv was the children's shared obsession with Reptar, a giant cartoon lizard who seemed to combine characteristics of Godzilla and Barney, the purple singing dinosaur. Many of their adventures revolved around Reptar merchandising opportunities: toys, ice-shows and, in the big-screen spin-off Rugrats in Paris (2000), a theme park, Reptarworld, a kind of radioactive lizard-orientated Euro Disney, populated by insufferable Parisians: yet another instance of an American impulse to link Godzilla with the French.
Godzilla meets confectionery
One of the most effective appropriations of the Godzilla mythos came in a witty 1980s TV advertising campaign for Chewits. To cries of "The muncher is coming," a giant lizard is seen rampaging through a city, devouring buildings. A scientist comes up with a solution. "It's a long shot, but it just might work." Next thing, the monster is presented with a giant packet of Chewits: as it tucks in, a beatific expression spreads across its face. An American news-reader style voice announces: "Chewits: even chewier than a 15-storey block of flats." To date, this statement has not been verified.