We are once more brought back upon it, and we shall be able to get an insight into the value which must necessarily be accorded to it.
The combat is the single activity in War; in the combat the destruction of the enemy opposed to us is the means to the end; it is so even when the combat does not actually take place, because in that case there lies at the root of the decision the supposition at all events that this destruction is to be regarded as beyond doubt.

It follows, therefore, that the destruction of the enemy's military force is the foundation-stone of all action in War, the great support of all combinations, which rest upon it like the arch on its abutments.

All action, therefore, takes place on the supposition that if the solution by force of arms which lies at its foundation should be realised, it will be a favourable one.

The decision by arms is, for all operations in War, great and small, what cash payment is in bill transactions.

However remote from each other these relations, however seldom the realisation may take place, still it can never entirely fail to occur.
If the decision by arms lies at the foundation of all combinations, then it follows that the enemy can defeat each of them by gaining a victory on the field, not merely in the one on which our combination directly depends, but also in any other encounter, if it is only important enough; for every important decision by arms--that is, destruction of the enemy's forces--reacts upon all preceding it, because, like a liquid element, they tend to bring themselves to a level.
Thus, the destruction of the enemy's armed force appears, therefore, always as the superior and more effectual means, to which all others must give way.
It is, however, only when there is a supposed equality in all other conditions that we can ascribe to the destruction of the enemy's armed force the greater efficacy.