By Captain B. H. Liddell Hart
Journal of the Royal United Service Institution, Vol. LXXV, Feb to Nov, 1930.
A series of articles have recently appeared in the Journal dealing with the Principles of War; but what seems to be far more important than abstract principles are practical guides. Napoleon knew that only the practical is useful when he gave us his maxims. Yet the modern tendency has been to search for a "principle" which can be expressed in a single word—and then needs several thousand words to explain it. Even so, these "principles" are so abstract that they mean different things to different men, and, for any value, depend on the individual's own understanding of war. The longer the search for such omnipotent abstractions is continued the more do they seem a mirage, neither obtainable nor useful, save as an intellectual exercise.
In contrast, certain axioms seem to emerge from a close and extensive study of war. These cannot be expressed in a single word, but they can be put in the fewest words necessary to be practical. They apply to strategy and tactics, unless otherwise indicated.
1. Always try to choose the line (or course) of least probable expectation—from the enemy's point of view.
2. Follow the line of least resistance—so long as it can lead you to any objective which would contribute to your underlying object. (In tactics this axiom applies especially to the use of your reserves. In strategy it applies to the exploitation of any tactical success).
3. Aim to make these two lines coincide by taking a line of advance which threatens alternative objectives. Thus you will have your opponent on the horns of a dilemma, and have the opportunity of swerving to gain whichever objective he guards least. (This axiom applies mainly to strategy, but should be applied where possible in tactics).
4. Ensure that both your plan and your dispositions (or formations) are elastic. Your plan should foresee and provide for a next step in case of success, or failure, or of partial success—which is the most common case in war. Your dispositions should be such as to allow for exploitation or alternation in the shortest possible time.
5. Don't lunge when your opponent can parry. A general has more resources, and should have more resource, than a bayonet-fighter. And in contrast, a body of troops has not the same power of quick recovery as an individual.
The experience of history shows that no effective stroke is possible until the enemy's power of resistance or evasion is paralysed. Hence no commander should launch a real attack upon an enemy in position until he is satisfied that such paralysis has developed. (Although worded tactically, this axiom should also be construed strategically).
6. Never renew an effort along the same line (or in the same form) after it has once failed. A mere reinforcement of weight is not sufficient change, for it is probable that the opponent also will have strengthened himself in the interval.
The critic may well advance the usual objection to the first axiom, "What will the enemy be doing meantime?" The historical answer that he will be doing the obvious and assuming that you are doing likewise. The experience revealed in history is sufficiently abundant to justify this hypothesis. Each side tries to frame the plan which seems most sound: it credits its adversary with similar soundness; and the result is stalemate. Then they attempt further moves on similar calculations—until at last exhaustion or despondency calls "time" to the struggle.
Very infrequently a commander has rejected the obvious and pursued the unexpected. He has won a decisive success—unless fortune has played foul. For luck can never be divorced from war, as war is part of life. Hence the unexpected cannot guarantee success. But it guarantees the best chance of it. That is why the successes of history, if not won by abnormally clever generalship, have been won by generalship that is outrageously foolish. Perhaps that is why Britain has had such a long run on the world's stage.