OK. I agree that "authoritarian" is often [+human], but I don't think it need always have that feature. For one thing, it may modify an abstract noun: "authoritarian regime". But, anyway, you are not happy with the word, so... another option.
"Authoritarianism" is not [+personal], but [+non-personal].
Salvador Allende - The Chilean President and the Agent of the KGB
... and
a 17-year period of authoritarianism began in the history of Chile. ... The period of General Augusto Pinochet's rule began in the history of Chile. ...
www.axisglobe.com/article.asp?article=397 - Cached - Similar -
I don't have my good dictionaries at hand, but this is the definition at
http://www.thefreedictionary.com for "authoritarianism": "a form of government in which the ruler is an absolute dictator".
On the basis this definition, another option would be:
"period of dictatorial rule":
HUNAHPU E IXBALANQUE: Por $50000 (Documental) - [ Translate this page ]
Afterwards, they foresaw
a prolonged period of dictatorial rule during which the regime would depend on the United States aid and arms… []… ...
hunapu-e-ixbalanque.blogspot.com/.../por-50000-documental.html