The conviction that there was utility in using the mind to devise cunning stratagems, ruses, and techniques of war to wage war effectively yet cheaply was a two-edged inheritance from antiquity. It encouraged an admirable proclivity to use one’s head in thinking about war, yet it also many times created a dangerous even disastrous over-confidence in the ability of the strategist to offset, through cleverness, quantitatively and perhaps also qualitatively superior material and human resources and power.

Byzantium missed many opportunities because of the adoption of this cautious military strategy. Yet her resources of man-power and materials were finite and the parsimonious and calculating employment of them in the late sixth through most of the eleventh centuries helped to reduce the chances of some gamble resulting in a total military catastrophe or the dissolution of the empire.

Risk minimization had its rewards; Byzantium assumed that the unknown exerted great effects upon the course and outcome of war. Therefore, she strove, even in an era of low lethality of weapons, for a multifaceted defensive strategy that did not rely exclusively on military force, but also on diplomacy, prudence, superior use of intelligence, and the exploitation of the enemy’s weaknesses.

From Walter Emil Kaegi, Jr., Some Thoughts on Byzantine Military Strategy