Which of the following is NOT one of the five fundamental sources of authority?

The five fundamental sources of authority serve as the foundational principles guiding operations and enforcement within maritime contexts. These typically include legal frameworks such as maritime law enforcement, customs law, and assistance provisions that pertain to aiding other nations or entities in enforcement matters.

International trade law, while significant in broader contexts involving commerce and trade regulations, does not directly pertain to the specific categories of authority that govern law enforcement powers at sea. Instead, it deals more with the regulations and agreements that facilitate trade between nations, which can indirectly influence maritime activities but are not categorized as a primary source of authority for law enforcement actions. Therefore, recognizing that international trade law does not fit within the five fundamental sources clarifies its role and relationship to maritime operations, distinguishing it from primary legal frameworks like those associated with maritime enforcement and customs law.