Original sentence: General Zachary Taylor came to the aid of the fort's defenders, which resulted in the Mexican General Mariano Arista ordering his troops to position on the nearby plains of Palo Alto, thereby lifting the siege
Edited sentence: General Zachary Taylor came to the aid of the fort's defenders, which resulted in the Mexican General Mariano Arista ordering his troops to position on the nearby plains of Palo Alto to defend themselves against the approaching enemy force, thereby lifting the siege