Godzilla can be viewed as a metaphor for the United States Air Force. In the years immediately following World War II, Japan's media was under the control of the occupying forces of the United States; making films describing the 'evil American bomber fleets' was not allowed. If you look at the original Gojira films, you find the following:
  • Gojira came from the Pacific, ostensibly from an American nuclear test. So did the Enola Gay.
  • Gojira makes his way towards Japan, inexorably, destroying various outlying islands in the process - a process which looks an awful lot like the American Pacific Theater bombing campaign.
  • Gojira is enormous, breaths fire, and destroys cities with firestorms and breakage. The U.S. Air Force was pretty big, dropped incendiary bombs, and destroyed cities with firestorms and high explosive bombing (breakage).
  • Gojira later on becomes the protector of Japan against other evil monsters. The U.S. Air Force later on became the protector of Japan against the Soviet Union and China.

...brings a whole new light to the monster movies. Now, if only I could figure out what the heck Gamera is a metaphor for...