As to the heavy infantry, an arm the deficiency of which at Athens is well recognised, this is how the matter stands. They recognise the fact that, in reference to the hostile power, they are themselves inferior, and must be, even if their heavy infantry were more numerous. (1) But relatively to the allies, who bring in the tribute, their strength even on land is enormous. And they are persuaded that their heavy infantry is sufficient for all purposes, provided they retain this superiority. (2) Apart from all else, to a certain extent fortune must be held responsible for the actual condition. The subjects of a power which is dominant by land have it open to them to form contingents from several small states and to muster in force for battle. But with the subjects of a naval power it is different. As far as they are groups of islanders it is impossible for their states to meet together for united action, for the sea lies between them, and the dominant power is master of the sea. And even if it were possible for them to assemble in some single island unobserved, they would only do so to perish by famine. And as to the states subject to Athens which are not islanders, but situated on the continent, the larger are held in check by need (3) and the small ones absolutely by fear, since there is no state in existence which does not depend upon imports and exports, and these she will forfeit if she does not lend a willing ear to those who are masters by sea. In the next place, a power dominant by sea can do certain things which a land power is debarred from doing; as for instance, ravage the territory of a superior, since it is always possible to coast along to some point, where either there is no hostile force to deal with or merely a small body; and in case of an advance in force on the part of the enemy they can take to their ships and sail away. Such a performance is attended with less difficulty than that experienced by the relieving force on land. (4) Again, it is open to a power so dominating by sea to leave its own territory and sail off on as long a voyage as you please. Whereas the land power cannot place more than a few days' journey between itself and its own territory, for marches are slow affairs; and it is not possible for an army on the march to have food supplies to last for any great length of time. Such an army must either march through friendly territory or it must force a way by victory in battle. The voyager meanwhile has it in his power to disembark at any point where he finds himself in superior force, or, at the worst, to coast by until he reaches either a friendly district or an enemy too weak to resist. Again, those diseases to which the fruits of the earth are liable as visitations from heaven fall severely on a land power, but are scarcely felt by the navel power, for such sicknesses do not visit the whole earth everywhere at once. So that the ruler of the sea can get in supplies from a thriving district.