遠交近攻/Yuan Jiao Jin Gong – Befriend the Far, Attack the Near
Original Text: If your formation is restricted & momentum hindered, it is advantageous to take what is near, thereby keeping harm at a distance. Fire above, a pool below.
Analysis: When your combat objectives are limited by geographical conditions, attacking a nearby enemy is advantageous while attacking a distant enemy is harmful. Opposing a distant enemy later can be advantageous, as it is possible to form a temporary alliance.