Principles of War:

Machiavelli's list of principles in The Art of War is a mixture of general principles and specific tactical maneuvers. For a more interesting approach I have taken the modern US list of principles of war and attempted to collect all that Machiavelli wrote on each.

Objective:

Machiavelli sees conquering and keeping territory at a profit as the political objective. The defeat of the enemy army is the strategic and tactical objective. While victory in battle is the objective of all armies, the general should never come to a general engagement unless forced to do so. It is more advantageous to defeat the enemy by destroying his will to resist through the use of psychological warfare and "peace campaigns". It is always possible to find allies within the opposing society who will act as a "fifth column". Even so, the use of all these other methods ultimately rests on having the undoubted ability to wage violent war in the open and to make war "short and sharp". Since war is caused by a "thirst for domination", it is foolish to try to appease an aggressor. It is almost always better to allow something to be taken by force than to yield it to the apprehension of force, because to yield from fear for the purpose of avoiding war merely encourages the enemy to try for more.

Offensive:

The offensive is the cardinal principle, because it enables the leader to keep ahead of his enemies and fortuna. By keeping the initiative the ruler can channel the course of history. The principle of the offensive must be applied flexibly. When external and internal evils arise at the same time temporizing may be necessary in order to be able to build up strength while one or the other dies out. Machiavelli discusses in some detail the relevant considerations one must take into account when deciding on taking the strategic offensive or defensive.

Mass and economy of force:

Machiavelli discusses Mass several times and urges the commander to never risk his whole fortune on only a part of his forces. He does not discuss the modern concept of economy of force explicitly.

Unity of command:

This is one of Machiavelli's important principles. He discusses both the necessity for unity of political and military leadership and the narrower question of unity of command within the command element of a field army.

Surprise and Security:

Machiavelli emphasizes the value of surprise and the consequent need for security. Secrecy of plans is one of the most important aspects of all operations. These principles rely on the use of deceit and the doctrine of appearances. Machiavelli incorporated a large part of Frontinus' Strategmata into his The Art of War.

Maneuver:

Machiavelli has little to say on this subject directly. However it is implicit in his advice not to rely on position defenses such as fortifications. Of course he devotes much attention to maneuvering in the political sense, but does not include much attention to it in his description of a set- piece battle.

Simplicity:

He does not mention this principle directly. He does note the requirement for simple orders and the likelihood of misunderstanding and confusion in battle.

Summary:

Machiavelli thus seems well aware of objective, offensive, mass, unity of command, surprise and security. He gives less attention to economy of force, maneuver and simplicity. These three principles are relatively new and were not stressed by the classical authorities upon whom Machiavelli relied.