The flank, both as a tactical maneuver and a literal side of a military formation, appears in poetry as a symbol of vulnerability and strategic cunning. Poets use flanking imagery to convey the calculated, almost predatory nature of military strategy, where victory often depends on exploiting an opponent's exposed weaknesses. The term also evokes physical proximity and danger, as soldiers positioned on the flank face particular exposure to sudden attack.

To flank is to attack or maneuver around the side of an enemy formation, a key tactical maneuver in battle. Flanking aims to strike the vulnerable sides or rear, where defenses are weakest and morale is low. A successful flank attack can break an enemy line and cause a rout. In poetry, flanking symbolizes strategic cunning, the indirect approach that avoids brute force. Related terms include enfilade, outflank, and turning movement. The phrase "threaten the flank" means to force the enemy to divert resources to defend against an impending attack. The classic tactical dilemma is to hold the line while preventing a flanking maneuver, a motif in military literature.