A few weeks ago I remarked on the relatively high current defense spending for the United States. In hindsight I think this was somewhat unfair, the proportion of the budget that the United States spends on defense is rather small in a world-historical context. I was reminded of this by a datum in The Age of Confucian Rule: The Song Transformation of China (highly recommended by the way), even this exceedingly civilian dynasty allocated ~80% of its budgetary outlays toward military expenses. Historical surveys of the Roman Empire also infer that most of the expenditure was directed toward paying for the legions, not bread & circuses. These two civilizations were relatively unique in that they placed great emphasis on the need for a civilian aristocracy who were soaked in literate culture (the first non-literate emperor of the Roman Empire took power in the early 6th century, and that fact may be a slander).
As a rule an incredibly high proportion of expenditures in pre-modern states which have left a non-trivial number of records produced by a bureaucracy (e.g., China, Rome, Byzantium, the early Caliphates) was allocated to the military. In those polities, such as the ones termed “feudal,” where exchanges between the individual and the powers that be occurred in the form of service and not currency (i.e., tax), there was a martial tinge to service (e.g., knights and samurai). The shift from hunter-gatherer bands to large political organizations seems to have produced an equilibrium of rent-extracting thugs whose competition for said rents generated the need for taxation to support their very existence in a vicious spiral. Of course there is also evidence that per capita violence has been decreasing since the days of yore, and concomitantly since the rise of social insurance and public utilities & works there has been a radical shift away from the a preponderant proportion of the state-sector budget being devoted toward the military (the Soviet Union seems to have perpetuated the pre-modern model). So I do not want to paint a trend toward red in tooth & claw.
Also, I do understand that some might argue that the pre-modern state captured far less of the economic output of a society in the form of taxes than the modern Leviathan. I will leave that debate to economic historians and their normative political philosophers, though I generally am of the position that the past was miserable by and large, and that the miseries of the present take a toll only because of the luxury which we have been habituated to.
Note: Many criticize the Confucian model of China for trapping that society in relative stasis. But at lease the political theorists of China generally understood the non-zero sum nature of military expenditure and warfare. Military pursuits were held in low esteem, even if it was acknowledged that they were needful.