The novel is more or less just a timeline or catalog of the Targaryen dynasty. You can draw any allegory you want from it and maybe the show is more heavy handed in stating that but from what I know GRRM simply used Fire & Blood as a way to catalog and expand on the lore of the Targaryens

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A dragon is very much the equivalent of a nuclear warhead. The only reason the Targaryen’s were in charge in the first place was because they had dragons at their disposal. After they went extinct, it was only a matter of time before the other houses got sick of the Targaryen’s, i.e., Robert’s rebellion against the Mad King

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