Who really owns the Caspian Sea?

Iran, Russia, Azerbaijan, Kazakhstan and Turkmenistan all share the Caspian Sea, but the five countries have never agreed on a fixed percentage each should own. Instead, they established a special legal regime after signing the Convention on the Legal Status of the Caspian Sea in 2018. This treaty set territorial waters up to 15 nautical miles and an exclusive fishing zone of 10 nautical miles for each nation.

However, it did not divide the entire sea into five equal shares. The Soviet Union collapsed in 1991, leaving Iran as one of the only two countries bordering the Caspian. The 1921 Treaty of Friendship with the USSR restored Iranian navigation rights, but no treaty specified a percentage for either Iran or the Soviet Union. Instead, they focused on shared use.

After the collapse, Azerbaijan, Kazakhstan and Turkmenistan became independent states, turning a bilateral agreement into a five-country negotiation. Some Iranian politicians argued for a 50% share, while others called for 20%. The 2018 convention allows each country to have territorial waters, a fishing zone, and control over the seabed through agreements between neighboring states.

Resource rights are mainly determined by these agreements, which is why offshore oil and gas rights are important. Iran has hydrocarbon potential in the Caspian, but its commercially recoverable resources remain uncertain and undeveloped. The southern Caspian is deeper than many areas explored by Iran's neighbors, making drilling more challenging and expensive.

Sanctions have made it harder for Iran to access international companies, financing, and specialized technology. The country has easier opportunities in its Persian Gulf and onshore oil fields. The Caspian Sea remains a complex issue with no single owner, but debates now focus on resource management, maritime boundaries, and preventing external military presence.