Three things have won conventional wars in this century; greater reserves of manpower, greater industrial potential and a reasonably functioning system of civilian administration. The strategy of the United States in the past two decades has been based on the hope that the second of these (in which it is supreme) would offset the first, in which the ussr was believed to have the edge. This theory was based on faulty arithmetic in the days when the only war envisaged was one against Russia, for the Warsaw Pact powers have no greater population than nato. The West was merely more reluctant to mobilize its manpower in conventional ways. However, at present the argument is probably more valid, for some of the Western states (like France) will almost certainly stay neutral in any world war that is likely, and China alone has more men than all the Western powers likely to fight in concert. At all events, whether the arguments were right or wrong, the United States has since 1945 put its money entirely on the superiority of its industrial power, on its capacity to throw into a war more machinery and more explosives than anyone else.

Consequently, it has been badly shaken to discover that a new method of winning wars has been developed in our time, and that it more than offsets the organization and industrial power of conventional military operations. That is guerrilla war, and the number of Goliaths who have been felled by Davids with slingshots is now very impressive: the Japanese in China, the Germans in wartime Yugoslavia, the British in Israel, the French in Indo-China and Algeria. At present the United States itself is undergoing the same treatment in South Vietnam. Hence the anguished attempts to pit bombs against small men behind trees, or to discover the gimmick (for surely there must be one?) which allows a few thousand ill-armed peasants to hold at bay the greatest military power on earth. Hence also the simple refusal to believe that it can be so. If the United States is baffled it must be due to some other—measurable and bombable—reason: to the aggressive North Vietnamese, who actually sympathize with their Southern brothers and smuggle trickles of supplies to them; to the terrible Chinese who have the nerve to possess a common border with North Vietman; and no doubt eventually to the Russians. Before common sense flies completely out of the window, it is therefore worth taking a look at the nature of modern guerrilla war.

There is nothing new about operations of a guerrilla type. Every peasant society is familiar with the ‘noble’ bandit or Robin Hood who ‘takes from the rich to give to the poor’ and escapes the clumsy traps of soldiers and policemen until he is betrayed. For as long as no peasant will give him away and as long as plenty will tell him about the movements of his enemies, he really is as immune to hostile weapons and as invisible to hostile eyes as the legends and songs about such bandits invariably claim.

Both the reality and the legend are to be found in our age, literally from China to Peru. Like the military resources of the bandit, those of the guerrilla are the obvious ones: elementary armaments reinforced by a detailed knowledge of difficult and inaccessible terrain, mobility, physical endurance superior to that of the pursuers, but above all a refusal to fight on the enemy’s terms, in concentrated force, and face to face. But the guerrilla’s major asset is non-military and without it he his elpless: he must have the sympathy and support, active and passive, of the local population. Any Robin Hood who loses it is dead, and so is any guerrilla. Every textbook of guerrilla warfare begins by pointing this out, and it is the one thing that military instruction in ‘counterinsurgency’ cannot teach.

The main difference between the ancient, and in most peasant societies endemic, form of bandit operation and the modern guerrilla is that the Robin Hood type of social bandit has extremely modest and limited military objectives (and usually only a very small and localized force). The test of a guerrilla group comes when it sets itself such ambitious tasks as the overthrow of a political regime or the expulsion of a regular force of occupiers, and especially when it sets out to do this not in some remote corner of a country (the ‘liberated area’) but over an entire national territory. Until the early 20th century hardly any guerrilla movements faced this test; they operated in extremely inaccessible and marginal regions—mountain country is the commonest example—or opposed relatively primiture and inefficient governments native or foreign. Guerrilla actions have sometimes played an important part in major modern wars, either alone in exceptionally favourable conditions, as with the Tyrolese against the French in 1809, or more usually, as ancillaries to regular forces—during the Napoleonic Wars, for example, or in our century in Spain and Russia. However, by themselves and for any length of time, they almost certainly had little more than nuisance value, as in Southern Italy where Napoleon’s French were never seriously inconvenienced by them. That may be one reason why they did not much preoccupy military thinkers until the 20th century. Another reason, which may explain why even revolutionary soldiers did not think much about them, was that practically all effective guerrillas were ideologically conservative, even if socially rebellious. Few peasants had been converted to left-wing political views or followed left-wing political leaders.