What is the right of approach (ROA) under international law?

• A. Under international law, the right of warships and other duly authorized vessels or military aircraft in International waters to approach any vessel in international waters and to verify its nationality through questioning.
• B. Right to detain any vessel found in territorial seas.
• C. Right to seize vessels suspected of piracy within 12 NM.
• D. Right to fire weapons when approaching a vessel.

Answer: (A)

The key idea is that the right of approach is the authority for warships and other duly authorized vessels or military aircraft to approach a vessel in international waters with the purpose of verifying its nationality by asking questions and checking identifying documents. This power helps ensure vessels’ flags and legal status are clear, which is important for enforcing international law, preventing illicit activities, and coordinating safety at sea. It applies when both vessels are in the high seas, not inside a coastal state's territorial sea, and it should be carried out in a calm, non-coercive manner focused on identification. Use of force isn’t part of this right; any firing would require separate justification under self-defense or other legal grounds, not the standard approach to verify nationality.

Detaining a vessel in territorial seas isn’t covered by this right, since territorial seas fall under a coastal state’s primary jurisdiction and detentions there follow different legal rules. Seizing vessels suspected of piracy within 12 nautical miles isn’t the typical scope of the right of approach, which centers on identification in international waters rather than immediate seizure within a coastal zone. Firing weapons during an approach would go beyond the non-violent verification purpose of the right of approach and would require a separate, lawful use of force.