Maneuvering · Provisions are the Foundation
We may take it then that an army without its baggage-train is lost; without provisions it is lost; without bases of supply it is lost.
Without supplies, food and reserves, an army collapses. Once the supply line breaks, no goal matters.
Maneuvering · Know Enemy and Terrain
We cannot enter into alliances until we are acquainted with the designs of our neighbours. We are not fit to lead an army on the march unless we are familiar with the face of the country. We shall be unable to turn natural advantages to account unless we make use of local guides.
If you do not know their plans or the terrain, and have no local guide, do not go in. Find out first, then move.