Did President Obama have legal authority to order Operation Geronimo and execute the plan

I need 3 key points as to why he had legal authority. The Hague rules of 1907, the geneva convention of 1949, and article 51 of UN Charter should help as 2 key points hopefully. Has to be 5 paragraphs, the intro, a paragraph for each key point and the conclusion. Would like as much references as possible preferably about 7. The case study of operation Geronimo is what was handed out for the persuasive essay. For the subject it’s for a military course