Sentence:  With the <WSD>Fetial</WSD> Law we are only imperfectly acquainted, but it seems to have been simply a law peculiar to the Romans, and regulating their conduct towards foreigners, and not properly an international law common to other nations, and determining on general principles their respective rights and duties. 
Meaning of the word marked with <WSD> tags:  Concerned with declarations of war and treaties of peace.