Ketevan Betaneli and Daniel Müller

A new legal regime for the Caspian Sea

Since the dissolution of the Soviet Union at the beginning of the 1990s, the legal status and the division of the Caspian Sea and its resources between its five coastal States (Azerbaijan, Iran, Kazakhstan, the Russian Federation, and Turkmenistan) has remained unresolved. Before 1991, the Caspian Sea had only two coastal States – the Soviet Union and Iran. They treated it as a lake and defined its legal status and their cooperation in the Caspian Sea by several bilateral agreements.

However, the new coastal States could not agree on the regime and on the division of the Caspian Sea. Some of them claimed that the Caspian Sea was subject to the rules of the international law of the sea and of the United Nations Convention on the Law of the Sea. Others considered that this body of water was a shared lake and that the coastal States needed to determine the legal status of the waters and the subsoil of the Caspian Sea between themselves. Iran, for instance, always considered the Caspian Sea to be a condominum over which all the coastal States jointly exercised sovereignty, including the right to an equal share in its abundant natural resources.

The Convention on the Legal Status of the Caspian Sea (the Convention) has now settled these longstanding difficulties by determining a sui generis regime for the Caspian Sea. The Convention was signed by the five coastal States on 12 August 2018. It will enter into force once all signatories have ratified it.

The Convention defines the legal status of the waters, the seabed, and the subsoil of the Caspian Sea. It regulates the use of natural resources and the airspace over the sea. The new regime for the Caspian Sea under the Convention establishes sovereign and exclusive rights for each of the coastal States in their respective “territorial waters” and seabed and subsoil “sectors”. It also recognizes far-reaching liberties for the common use of the Caspian Sea by all of the coastal States.

Key issues addressed by the Convention

The Convention reserves all rights over the Caspian Sea and its resources to the five coastal States. It excludes access to and the use of the Caspian Sea by third States.

The key issues covered by the Convention concern:

  • the legal status of the waters, the seabed and the subsoil;
  • exploitation of the natural resources of the Caspian Sea and its seabed;
  • a comprehensive fisheries regime;
  • navigation in the Caspian Sea;
  • transit from and to the High Seas;
  • the protection of the ecological system and biodiversity; and
  • dispute resolution.

For more details concerning the regime envisaged under the Convention, please consult our Briefing on the Freshfields Knowledge Hub.

The text of the Convention is available here.


Dr. Daniel Müller is avocat at the Paris bar and an associate in the international arbitration group of Freshfields Bruckhaus Deringer LLP. 

Ketevan Betaneli is a knowledge lawyer in the international arbitration group of Freshfields Bruckhaus Deringer LLP.