In the Annals, the Roman historian Tacitus argued that Roman policy was culturally constrained by the ever increasing demand for luxury items amongst its citizens, ensuring that Rome was entirely dependent on its provinces for its continued existence. Of course this situation was commonly exploited for financial gain by the governors of these provinces. You see, by the time of the early Empire, Romans had almost completely forsaken the civic virtues of the early Republic — above all, the idea that one might sacrifice private goods for the public benefit.
When the emperor Tiberius was called upon by the Senate (not exactly a paragon of austerity) to consider placing more constraints upon the consumption of wealthy Romans, Tacitus has him reply that even the people demanding these restrictions would chafe under them and civil strife would be assured. He declares that “victories over the foreigner taught us how to waste the substance of others; victories over ourselves, how to squander our own” (Annals 3.54).
This locked the Roman Empire into a socioeconomic situation in which disruptions in the provinces very quickly became disruptions in Rome, as Roman politicians preferred “to cultivate Africa and Egypt [rather than Italy], and trust the life of the Roman people to ships and all their risks” rather than risk reforming public policy to reduce their need for so many ships (12.43). There were simply too many private interests and too few cultural norms left to motivate personal consideration of the public good.