Hi David.

>> "As my stories all have a political and social slant instead of a
>> physical-science slant, I think the one author who influenced me most
>> was Nicco Machiavelli, with H. L. Mencken placing and Karl von
>> Clausewitz showing." - H. Beam Piper, "Double: Bill Symposium"
>> interview [1]
>
> https://en.wikipedia.org/wiki/Ibn_Khaldun
>
> for collapses of empires

I'm sure that Beam (and Otto Harkaman) would have really appreciated Ib'n Khaldun's approach to history but it would seem he wasn't yet well-enough known -- at least among lay historians in English-speaking North America -- for Beam to be aware of the Arab historiographer during the time he was writing.

Cheers,

David
--
"And I don't read inside-dope magazines, or science fiction. I read carefully substantiated facts." - Max Pottgeiter (H. Beam Piper), "The Edge of the Knife"