Final answer:
The subject of this question is Social Studies, and it relates to military strategies, army command, and soldier conduct.
Step-by-step explanation:
The subject of this question is Social Studies. It relates to topics such as military strategies, army command, and soldier conduct. The question refers to specific texts like the Soldier's Creed, the Scout Law, the Code of Conduct, and the General Orders for Sentries. These texts and the provided information from Sun Tzu's 'The Art of War' and other sources give insights into military principles and practices.