Dr. Sadao, despite being a loyal Japanese citizen during wartime, chose to save the life of the wounded American soldier out of his humanitarian spirit. Once the soldier recovered, Dr. Sadao planned his safe escape. He provided him with a boat, food, water, extra clothing, and even a torch to signal when he reached a safe island. This careful planning ensured that the soldier could leave without being detected by Japanese authorities, thus ensuring his safety and protecting himself from suspicion as well.
Final Answer:
Dr. Sadao arranged a boat, food, clothes, and a torch for the American soldier, enabling his safe and secret escape without detection by Japanese authorities.