Original sentence: The vast amounts of war materiel that were airdropped onto these islands during the Pacific campaign between the Allies and the Empire of Japan necessarily meant drastic changes to the lifestyle of the islanders, many of whom had never seen Westerners or Easterners before
Edited sentence: The vast amounts of war materiel that were airdropped onto these islands during the Pacific campaign against the Empire of Japan necessarily meant drastic changes to the lifestyle of the islanders, many of whom had never seen Westerners or Easterners before