Foraging could force an army to keep advancing

An army supplied overland needed large wagon trains or had to live off the land. Foraging could sustain it for a short period, but feeding the troops consumed the resources around their position. Once those supplies were exhausted, remaining in place became difficult, and returning over the same route led back through country already stripped of food. Continued movement became a logistical necessity, even when holding ground would have suited the campaign. This pressure could encourage an offensive spirit while making the army harder to organize and sustain.