This article examines whether a Detaining State is obliged to recognize prisoner of war status for its own nationals under Article 4A of the 1949 Geneva Convention III. It begins with an assessment of that article from the perspective of established principles for construing treaty provisions. It then adds context to that assessment by examining relevant scholarship and State practice regarding its prescriptions before and after the Convention’s negotiation and adoption. Although it concludes that denying prisoner of war status to a national of the Detaining Power is the more persuasive interpretation of Article 4A, it concludes by highlighting the practical challenges of determining nationality that Detaining States may confront