how does Sadao justify that he is saving an enemy's life?

The conflict between medical ethics and patriotism is depicted quite subtly but with precision by Pearl S Buck. Sadao feels conflicted as a doctor to allow someone to die without medical attention being close at hand just because he belonged to the enemy camp. Ethics dictated that he should answer the call of humanity before the call of the nation. Therefore, Sadao refuses to be swayed by patriotic fervour and decides to help the man in spite of the great risk involved in it. He could be seen as a traitor for the enemies by harbouring an American prisoner but he cannot let that get in the way of performing his duties as a doctor. ​Sadao comes across as a dignified and respectful character who valued his duty as a doctor over his patriotic fervour. He had been indoctrinated in the belief that one's future depended on how he chose to shape it. Taking from that same principle, he did not allow his patriotic sentiments interfere with his duty as a doctor and above all his human instincts in saving the life of a fellow human being. With dogged determination, he worked towards the betterment and safety of his guest in spite of the danger that was involved in harbouring an enemy.