Leo Tolstoy in War and Peace describes (Book IV, Part Three, Chapter 1) the means by which the Russians defeated Napoleon in the war of 1812. He uses a metaphor which still seems relevant today:
Let us imagine two men coming out to fight a duel with rapiers in accordance with all the rules of the art of fencing: the swordplay has gone on for some time; suddenly one of the duelists, realizing that he has been wounded and that it is not a joke but a matter of life and death, flings down his sword, seizes the first cudgel that comes to hand, and starts brandishing it. Then let us imagine that this combatant, who so sensibly employed the best and simplest means of attaining his end, was, for all that, inspired by the traditions of chivalry, and, wishing to conceal the nature of the conflict, contended that he had won in accordance with the rules of the art. One can imagine what bewilderment and obfuscation would result from such an account of the duel.
The fencer who insisted on the duel being fought according to the rules of the art was the French army; the opponent who flung down his sword and snatched up the cudgel was the Russian people; the men who attempted to explain it all according to the rules of swordsmanship were the historians who have written about the event.
In the next chapter, Tolstoy continues:
One of the most palpable and advantageous departures from the so-called rules of warfare is the action of scattered groups against men compressed in a mass. This type of action always occurs in wars that have taken on a national character. In such engagements, instead of one mass of men making a stand against another mass, small groups of men disperse and make isolated attacks, instantly fleeing when attacked by superior forces, and then attacking again when the opportunity presents itself. This was done by the guerrillas in Spain, by the mountain tribes in the Caucasus, and by the Russians in 1812.
Tolstoy then analyzes the vital importance of the spirit of the individual fighters --- a factor which, he argues, is far more important than the size of the forces, the quality of their weaponry, or any purported genius of the commanders on either side.
(from the Ann Dunnigan translation; see also see also TruthInBattle (11 Feb 2001), OozeOnVerst (22 Sep 2004), IrresistibleAttraction (4 Oct 2004), InfiniteSky (15 Oct 2004), UntutoredVoice (3 Nov 2004), StrippedThreads (15 Nov 2004), PatienceAndTime (11 Jan 2005), ...)