Roman elites' unwillingness to go on long military campaigns themselves and increasing reliance on foreign personnel who quickly figured out that it is easier and safer to simply turn against their paymasters than risk lives in far away lands.

Im not making the connections the top comment is. Her SPQR books are nice alternative history from a real historian. At a guess the parent comment is referring to some cultural aspects based on earlier roman and not our current judeo-christian values in the west. An emphasis on biological advancements, moralality that serves status hierarchy and empire, “polycule” style relationships in military and socioeconomic units, a different view on “sanctity of life.” Off the top of my head.