In conducting offensive operations, two cases are to be distinguished. In the first place, the object may be to surprise the enemy, either at the commencement of the war, or on the opening of a campaign. Secondly, it may he intended to make an attack upon an enemy who is prepared to receive us. The first case is evi dently the most advantageous; but, in order to insure success, it is necessary to keep the enterprise secret, and to execute it with the greatest possible celerity.
When it is proposed to surprise the enemy at the commencement of a war, it is necessary not only to have a considerable number of troops constantly on foot, but that these troops should he in a state fit for immediate service. Baggage and artillery horses must be in readi ness ; a large store of war ammunition must be pre pared in the neighbourhood of that quarter where the war is to be commenced ; and magazines must be form ed for the maintenance of the troops. All these pre parations, too, must be made with such care, that the enemy may not be able to discover the object. When all the necessary preparations have been made, it must then be determined what are the most decisive measures that can be accomplished by a surprise ; how far we can get the start of the enemy ; and whether we shall have sufficient time to execute the most decisive measure, or must be content, from want of time, with something less decisive. These questions must be determined accord ing to the circumstances of each case. Among the ob jects to be accomplished by a surprise are the follow ing : To seize the enemy's capital ; to take possession of one of his most important provinces ; to separate his army, so as to prevent it from being drawn together ; to attack one of his principal allies, and force him to make peace. When none of these most important ob jects can be accomplished, we must endeavour to obtain possession of the means of prosecuting the war with ad vantage, by occupying the passes which lead into the enemy's country, or making ourselves roasters of a river which opens into it ; or by carrying a fortress which af fords the key to it, &c.
In all such enterprises, however, we must keep in view the means of defence which the enemy can oppose to us. These, in general, are : 1. Fortresses ; 2 Rivers ; 3. De files ; and 4. The army itself. In the first case, the whole undertaking will commence with a siege of the most im portant fortress. The importance of a fortress depends upon the advantages wnich the possession of it will af ford us, or the disadvantages to which the loss of it will subject the enemy. Sieges, therefore, must never be
formed, unless, 1. When the fortresses are placed on the passes which lead into the enemy's country, and iu such a manner that you cannot penetrate till you are masters of them. 2. When they are un your com munication, and the country does not furnish the ne cessary subsistence. 3. When they are necessary, in order to cover the magazines you form in the country itself, to facilitate your operations. 4. When they contain considerable magazines of the enemy, and such as are essentially necessary to him. 5. Wnen the conquest of them is necessarily followed by that of some considerable district, which enables you to sepa rate your armies into winter-quarters in the enemy's country. All fortresses, which are of no essential use in our farther advance, or to our safety in case of a retreat, should be demolished as soon as they are taken.
Rivers and defiles may he passed without difficulty in the case of a surprise ; but they should be passed at such places as lead most safely and directly to the great object, where posts may be established, to enable us to advance, or, if necessary, to secure a retreat. If the nature of the country be such, that it can be covered by the army alone, that is, if it be an open country, we must immediately push forwards towards that object, which, if attained, will prove decisive of the war,--as, for example, the capital ; or, if that be impossible, we must begin by occupying some tenable place, for the purpose of establishing magazines, of enabling us to ad vance, or to maintain the conquered country, or to se cure a retreat.
In the case of a surprise at the opening of a campaign, we can never expect to find the enemy so unprepared as at the commencement of a war. It is necessary, therefore, that such an undertaking should be previous ly well considered ; for as troops are called upon, in such a case, to act at a season when they are exposed to great hardships in the field, we ought to calculate whether the probable success will compensate the cer tain expence of men and money. There are occasions, indeed, when the advantage of a few days over the ene my may be decisive ; and these should never be over looked. But when several weeks are required, it will be found much better in most cases to let the troops rest, and wait for the time when the war may he prose cuted without any such evident waste of our recources.