"Asymmetry is a concept commonly and mistakenly used in the analysis of 21st Century warfare, even though it is as old in human terms as conflict itself, and is therefore not unique to current situations. Like the biblical story of David and Goliath, ideally combat has always been asymmetrical, for opposing forces tend to fight on equal terms only if battle cannot be avoided.

'Symmetry' and 'Asymmetry' are the ends of a continuous spectrum that assumes a common measure between comparable things. Whatever the measure used something is more or less symmetrical or asymmetrical when it is compared with something else.

Because such comparative analyses of 21st Century warfare are not fruitful, in order to understand current and potential armed conflict better, asymmetry needs to be replaced with the systems concept of 'force disparity.'

Force disparity is an absolute disjunction between the forces available to the opposing sides. It is not just difference in degree, but in kind. Force disparity in the context of 21st Century warfare recognizes that combatants may be so utterly different in terms of the nature and equipment of their respective militaries that nothing useful or meaningful is to be gained by a comparison of the two sides. Either the military forces are incommensurable - what value is there in comparing Hellfire missiles against pointed sticks? - Or the disparity is so absolute that the two sides will never be fielding forces that are even remotely comparable in numbers, equipment or training."