There's no doubt that the
Godzilla films were, at least initially, an attempt by Japanese culture to deal with the horror of the atomic bombs. You see the same thing in anime titles such as
Grave Of The Fireflies, as well as many of the more apocalyptically-minded series like
Neon Genesis Evangelion, which are replete with catastrophic imagery.
However, in the later Godzilla films, such as
Godzilla Vs. The Smog Monster, Godzilla becomes a hero of sorts, defending Japan against all sorts of evils.
Godzilla, Mothra, and King Ghidorah: Giant Monsters All-Out Attack puts a new take on this, though.
In the movie, Godzilla is portrayed, not as a dinosaur resurrected by nuclear tests, but rather as a conglomeration of all of the souls that suffered under Japan during World War 2 (they explain that using some really cheesy, pseudo-mystical mumbo-jumbo). Hence, Godzilla's rampages are actually Japan's penance, reminding them of their past sins whenever the people grow complacent and forgetful.
Japan's guardian monsters (Mothra, Baragon, and King Ghidorah) then come to rescue, eventually combining their powers to defeat Godzilla - thereby exorcising Japan's demons. Which I suppose you could read as a metaphor for Japan feeling like it's been held accountable for past sins long enough, and is ready to move on. Of course, it doesn't help the message that the film becomes an absolute mess in the final act, full of horrible CGI, disjointed storylines, annoying characters, etc. Up until the final third or so, the movie is actually pretty enjoyable, and somewhat thought-provoking. At least, as much as a
Godzilla movie can be.

If you're curious, here's
my full review.