<Ul> <Li> A flanking maneuver or single envelopment consists of one enveloping force on a flank . attacking one of the enemy's flanks . This is extremely effective if the holding forces are in a well defensible spot (e.g. Alexander the Great's hammer and anvil at the Battle of Issus) or if there is a strong, hidden line behind a weak flank (e.g. Battle of Breitenfeld (1631) and Battle of Rocroi). </Li> <Li> A pincer movement or double envelopment consists of two simultaneous flanking maneuvers . Hannibal devised this strategy at his tactical masterpiece, Cannae . Later on, Rashidun Caliphate General, Khalid ibn al - Walid applied the maneuver in decisive battle against Sassanid Empire during Battle of Walaja . Early in World War II the Germans frequently employed this tactic and encircled huge numbers of the enemy during the Blitzkrieg attacks on both the Western Front during the Battle of France and during Operation Barbarossa on the Eastern Front . </Li> <Li> An encirclement whereby the enemy is completely surrounded and isolated in a pocket . The friendly forces can choose to attack the pocket or invest it (to stop resupplies and to prevent breakouts) and wait for a beleaguered enemy to surrender . </Li> <Li> A vertical envelopment is "a tactical maneuver in which troops, either air - dropped or air - landed, attack the rear and flanks of a force, in effect cutting off or encircling the force". </Li> </Ul> <Li> A flanking maneuver or single envelopment consists of one enveloping force on a flank . attacking one of the enemy's flanks . This is extremely effective if the holding forces are in a well defensible spot (e.g. Alexander the Great's hammer and anvil at the Battle of Issus) or if there is a strong, hidden line behind a weak flank (e.g. Battle of Breitenfeld (1631) and Battle of Rocroi). </Li> <Li> A pincer movement or double envelopment consists of two simultaneous flanking maneuvers . Hannibal devised this strategy at his tactical masterpiece, Cannae . Later on, Rashidun Caliphate General, Khalid ibn al - Walid applied the maneuver in decisive battle against Sassanid Empire during Battle of Walaja . Early in World War II the Germans frequently employed this tactic and encircled huge numbers of the enemy during the Blitzkrieg attacks on both the Western Front during the Battle of France and during Operation Barbarossa on the Eastern Front . </Li> <Li> An encirclement whereby the enemy is completely surrounded and isolated in a pocket . The friendly forces can choose to attack the pocket or invest it (to stop resupplies and to prevent breakouts) and wait for a beleaguered enemy to surrender . </Li>

What is vertical envelopment and why is it an effective military tactic