不明于敌人之政，不能加也；不明于敌人之情，不可约也；不明于敌人之将，不先军也；不明于敌人之士，不先陈也。· Do not launch a military expedition against an enemy country until information about its politics has been obtained; do not make a military decision until information about the enemy troops is acquired; do not take military action until information about the enemy commander has been gained; do not form a battle array until information about the enemy's formation has been studied.