What is the scope of the safe conduct granted by the Imam (ruler) versus that granted by individual Muslims?

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The safe conduct issued by the Imam to all non-Muslims or individuals among them is valid because his authority is general over the Muslims. The safe conduct of the commander is valid for the specific group of polytheists arrayed against him, but concerning others, he is treated like an individual Muslim, as his authority is restricted to fighting those specific enemies. The safe conduct of individual Muslims is valid for one person, ten people, a small caravan, or a small fort, based on Umar's ratification of a slave's Aman to people of a fort. However, the Aman of an individual Muslim is not valid for the people of an entire city, district, or a large group because this leads to suspending Jihad and encroaching upon the Imam's authority.