The Kazakh coastal city of Aktau hosted Aug. 12 the fifth summit of the five Caspian littoral states — Iran, Russia, Kazakhstan, Azerbaijan and Turkmenistan — on the legal status of the Caspian Sea. The presidents of the five countries signed a landmark convention on the legal status of the Caspian, ending 21 years of disagreements over how to coordinate their economic, political and security plans for the largest inland salt sea in the world. On the sidelines of the summit, six agreements were also signed on issues such as economic cooperation, transportation and fighting organized crime.

Although the five presidents at the summit praised the convention as a significant step in resolving longstanding disagreements and a prelude to further cooperation in the Caspian region, Iranian public opinion showed an overall negative reaction to the accord. Most of the criticisms were based on the claim that Iran has ceded its historical rights in the Caspian to its northern neighbors.

Debates over the issue intensified especially as Reformist parliament member Mahmoud Sadeghi speculated in a tweet that Iran’s share of the Caspian has been reduced from 50% to 11%, comparing the convention signed in Aktau with the 1828 Treaty of Turkmenchay, in which great swaths of Iran’s territory were ceded to Tsarist Russia. The tweet was followed by a wave of similar accusations against President Hassan Rouhani’s administration on Persian-language social media.

However, a great part of the controversy seems to be rooted in the false assumption that prior to the collapse of the Soviet Union in 1991, Tehran and Moscow had divided the Caspian on a 50-50 basis, and there were legal provisions for equal access to the sea. In fact, the rules governing activities in the Caspian before the Soviet collapse had been derived from the 1921 Russo-Persian Treaty of Friendship and the 1940 Treaty of Commerce and Navigation. However, none of those treaties contained an exact division of the seabed or surface, referring just to the joint usage of the Caspian Sea by the two sides. However, almost through the whole Soviet period, the Russians had the upper hand in the inland sea, limiting Iran to a restricted area adjacent to its coast.