Code for Unplanned Encounters at Sea (CUES)

Code for Unplanned Encounters at Sea (CUES)
Name	Code for Unplanned Encounters at Sea (CUES)
Adopted	2014
Location	Istanbul
Participants	United States Department of Defense, Chinese People's Liberation Army Navy, Association of Southeast Asian Nations, India, Japan, Australia
Language	English

Code for Unplanned Encounters at Sea (CUES) is a multilateral, non-binding arrangement designed to reduce the risk of incidents between naval vessels and aircraft during unplanned encounters. Originating from maritime dialogues among Pacific and Indian Ocean powers, it seeks to standardize communications and maneuvering protocols to prevent escalation between states such as United States Department of Defense, People's Republic of China, Japan Maritime Self-Defense Force, Royal Australian Navy, Indian Navy, and members of the Association of Southeast Asian Nations. CUES complements regional confidence‑building measures and has been referenced in interactions involving actors like the NATO, ASEAN Regional Forum, and bilaterals between Russia and Western navies.

Background and development

CUES traces conceptual roots to Cold War confidence‑building measures exemplified by the Incidents at Sea Agreement between the United States Navy and the Soviet Navy and to later cooperative frameworks forged after crises including the 1999 Kargil War and the 2001 Hainan Island incident. Discussions intensified in multilateral meetings such as the Western Pacific Naval Symposium and the ADMM-Plus fora where participants like the Japan Maritime Self-Defense Force, Royal Australian Navy, Republic of Korea Navy, Indian Navy, and People's Liberation Army Navy sought procedural means to manage encounters. The 2014 adoption in Istanbul was influenced by states including the United States Department of Defense, Ministry of National Defense (People's Republic of China), and regional actors tied to the East Asia Summit.

Purpose and principles

CUES aims to prevent miscalculation among seafaring services such as the United States Navy, People's Liberation Army Navy, Royal Navy, French Navy, Japan Maritime Self-Defense Force, and Indian Navy by prescribing communication, maneuvering, and signaling conventions. It emphasizes safety, predictability, and de-escalation in interactions among platforms like aircraft carriers of the United States Navy, destroyers of the Royal Australian Navy, and patrol vessels engaged by the Philippine Navy. Principles reflect precedents set in agreements like the United Nations Convention on the Law of the Sea negotiations and operational practices from incidents involving actors such as HMS Defender-class interactions, the USS McCain collision responses, and aerial encounters involving People's Liberation Army Air Force units.

Key provisions and procedures

CUES prescribes standardized voice communications, signaling, and maneuvering protocols for surface, subsurface, and air contacts, drawing on language used by the International Civil Aviation Organization and naval practice from fleets including the Russian Navy and Royal Canadian Navy. Procedures include predefined radio calls, use of internationally recognized signals, overtaking and crossing rules, and minimum safe distances informed by incidents like collisions involving USS Fitzgerald and concurrent exercises with the Royal Navy. It provides templates for bridge-to-bridge communication among officers of the watch from navies such as the Republic of Korea Navy, Royal Thai Navy, Indonesian Navy, and guidance for aircrew interactions involving units associated with the United States Pacific Fleet and People's Liberation Army Naval Air Force.

Signatory states and adoption

CUES was endorsed by delegations representing a broad swath of maritime actors at gatherings including the Western Pacific Naval Symposium, ASEAN Regional Forum, and the ADMM-Plus meetings; participants include the United States Department of Defense, Ministry of National Defense (People's Republic of China), Japan Maritime Self-Defense Force, Indian Navy, Royal Australian Navy, Republic of Korea Navy, Royal Navy, French Navy, Russian Navy, and numerous ASEAN militaries such as the Philippine Navy and Indonesian Navy. Adoption is declaratory rather than treaty‑based, mirroring patterns seen in instruments like the Proliferation Security Initiative and cooperative arrangements between the United States and United Kingdom.

Incidents and case studies

CUES has been cited in responses to maritime and air encounters in the South China Sea involving the People's Liberation Army Navy and Royal Australian Navy ships, aerial interactions between People's Liberation Army Air Force fighters and United States Air Force assets, and surface confrontations near the Spratly Islands implicating the Philippine Navy, Vietnam People's Navy, and Malaysian Armed Forces. Analysts reference crises such as the 2001 Hainan Island incident, near collisions involving USS Chung-Hoon, and shadowing episodes with vessels from the Russian Navy to assess CUES efficacy. Exercises like the RIMPAC multinational drills and trilaterals involving Japan, United States, and Australia have used CUES principles to structure safety protocols.

Relationship to international law and naval protocols

CUES operates alongside instruments such as the United Nations Convention on the Law of the Sea, customary practice codified in documents associated with the International Maritime Organization, and bilateral protocols like the Incidents at Sea Agreement. It is non‑binding and intended to complement legal obligations undertaken by navies including the United States Navy, People's Liberation Army Navy, and Royal Navy rather than substitute for treaties adjudicated by bodies such as the International Tribunal for the Law of the Sea. CUES interfaces with operational doctrine from services like the Japan Maritime Self-Defense Force and guidance from multinational coalitions such as the NATO naval commands.

Criticisms and limitations

Critics from forums including security think tanks and parliamentary committees of countries like the United Kingdom, United States, Australia, and Japan note that CUES is non‑binding, limited in geographic scope, and ambiguous when applied to complex contested situations like those in the South China Sea and near the Kurile Islands. Observers reference state behavior by the People's Republic of China, Russia, and others as demonstrating gaps between CUES rhetoric and practice, and point to incidents involving the People's Liberation Army Navy and United States Navy where adherence has been contested. Legal scholars compare CUES to binding regimes such as the United Nations Convention on the Law of the Sea to underscore enforceability concerns.

Category:Naval agreements