Conventional military weapons aren’t effective against a Godzilla, and nukes only strengthen them. Effective means are strong basic chemicals, another Godzilla class monster, or fricken lasers.

It’s kind of a tangible realization of sense of grave defeat from WWII among Japanese population immediately post-war, hence weakened emphasis on militaristic means in its plot.

Interesting points. I didn't make those connections, watching the 2019 American version King of Monsters yesterday. Bailed out one hour in feeling too much sensory overload. Might go finish it now.