The Calculus Of Battle

This is Steven Petrick posting:

Most battles appear to be straightforward things. Side A arrived with more combat power than Side B, and Side B is crushed. It is, however, not always that simple.

According to that simple formula, Cannae should have been a disaster for Hannibal. Instead his outnumbered Carthaginian army (largely composed of non-Carthaginian mercenaries) inflicted a crushing defeat on the largest army Rome had yet gathered in one spot.

This is where leadership comes in. One should never, as the leader of a military force, assume that numbers alone will allow you to prevail. Every battle should be approached with the view that the enemy may have some trick up his sleeve. (Hannibal lured the Romans into massing against his center, using his superior cavalry to route the Roman and Roman allied cavalry before closing the trap on the rear of the Roman infantry).

Hannibal, it must be remembered, chose the battlefield, and even chose the Roman Commander for the day of the battle. (The Roman forces were composed of two Consular Armies, so each consul acted as over all commander on alternating days, and Hannibal chose to offer battle when Varro, the more aggressive of the two, was overall commander.)

It is hardly the only case.

The Battle of Lepanto was a disaster for the Ottoman empire at least in part because they had a “tradition of victory.” They had always defeated their Christian foes at sea before, and obviously would do so again. While their numerical advantage was nowhere near as great at the better that two-to-one the Romans enjoyed at Cannae, the Ottomans did bring a superior number of ships to the battle. They failed to realize that their foes were going to be doing something different: use heavy cannon in a sea battle. The result was the virtual annihilation of the Ottoman fleet. While the Ottomans would rebuild their fleet and gain some victories in the following decades, they never really recovered from the disaster (unlike the Romans after Cannae).

In both cases part of the reason for the defeat was the commander of the losing side not being able to imagine that his opponent might actually be able to something in the face of his obviously superior position. Disaster followed as night follows day.

Here in Texas the battle of San Jacinto stands out. Santa Anna knew the Texican revolutionaries could do anything to his Army. After all, the Texicans were a rabble, while he commanded a professional army that had been pursuing them. So confident was he that he did not even bother to post guards. The result once again was disaster.

Never write off an opponent, no matter how much you judge the odds to be in your own favor. He may know something you do not: something about the ground, or something about a new technology, or simply some flaw in your own tactics that until that day has served you in good stead. Always expect the unexpected, and remember that if you are committing your last reserve (and you must be prepared to commit it, as sometimes holding your last reserve uncommitted will itself cost you the battle), you should have a plan to reconstitute a new reserve in case the enemy’s plan is to hit you once your last reserve has been used.