It was necessary for him therefore to assume the offensive.

Only by a bold advance, and by taking his enemy to some extent unprepared, and so at a disadvantage, could he hope to succeed in his audacious project.

It is not easy to see that he could have had any considerable party among the Persians, or any ground for expecting to be supported by any of the subject nations.

His following must have been purely personal; and though it may be true that he was of a character to win more admiration and affection than his brother, yet Artaxerxes himself was far from being unpopular with his subjects, whom he pleased by a familiarity and a good-nature to which they were little accustomed.

Cyrus knew that his principal dependence must be on himself, on his Greeks, and on the carelessness and dilatoriness of his adversary, who was destitute of military talent and was even thought to be devoid of personal bravery.
Thus it was important to advance as soon as possible.