By Eduard Arakelyan
The Iranian government has approved a bill on the ratification of the 2018 Convention on the Legal Status of the Caspian Sea and submitted it to parliament.
The bill was approved under an “urgent procedure,” meaning it will undergo expedited review in the relevant parliamentary committees. In addition, an upcoming Caspian summit is scheduled to take place in Iran in August, with the participation of the leaders of the Caspian littoral states, and Tehran was expected to make progress on this issue before the summit. Iran is the only signatory country that has not yet ratified the agreement in parliament.
The Convention has remained unratified for nearly eight years due to serious domestic disagreements. The main concerns relate to the delimitation of the Caspian Sea, national security risks, and economic consequences.
The document’s return to the political agenda comes amid Iran’s military confrontation with the United States and Israel, as well as a large-scale restructuring of the region’s transport and energy architecture. For Tehran, the ratification issue is linked to Iran’s future role as an energy power, transit hub, and regional actor.
One of the external factors accelerating the process is Russia’s position.
Moscow is interested in the final establishment of the legal regime of the Caspian Sea and supports the completion of the ratification process by all five Caspian littoral states.
In December 2025, Russian Foreign Minister Sergey Lavrov stated that Moscow expected Iran to complete the ratification process before the next Caspian summit, which was planned to take place in Tehran.
For Russia, the completion of the process aims to consolidate a new framework of interaction in the Caspian and reduce the risks of new territorial disputes. Moscow is a strategic partner of Tehran and is interested in continued coordination.
At the same time, the development of new routes through Azerbaijan and Turkey could potentially strengthen projects that will compete with both Russian and Iranian routes. It is notable that Russia is simultaneously interested in the legal conclusion of the process while inevitably facing the consequences of the potential strengthening of alternative infrastructure.
Before the signing of the Convention, Iran based its position on the 1921 and 1940 Soviet-Iranian agreements, which treated the Caspian as an area of joint use. After the collapse of the Soviet Union, the creation of a new legal regime became necessary.
Among Iranian experts, there are concerns that approval of the document would weaken the country’s position. Tehran had long advocated for an equal division of the Caspian, with 20% allocated to each country. However, the current configuration could result in a smaller sector — approximately 9–13% of the waters.
Security and risks
The Convention prohibits the presence of armed forces of states that do not have access to the Caspian Sea.
However, other forms of cooperation between Caspian countries and external actors also exist — including intelligence and logistical cooperation. This potentially leaves room for indirect military presence or intelligence activities by external states through the territory of their Caspian partners.
Following the start of the war with Israel and the United States, the issue of using neighboring countries’ infrastructure has gained new significance for Tehran. Iranian expert assessments consider scenarios in which maritime infrastructure of regional countries could be used by external forces for military purposes. One hypothetical example discussed is the possible appearance of naval assets in the Caspian Sea linked to external actors and operating under the flag of a neighboring Caspian state. From Tehran’s perspective, such a scenario could create additional security challenges given the proximity of the coastal area to Iran’s strategic facilities, including the country’s capital.
Energy, the South Caucasus, and new transport corridors
The main economic consequences of the Convention are related to changes in the rules governing the construction of underwater pipelines.
Previously, Iran and Russia could block such projects by citing the absence of a final legal regime and environmental concerns.
After the adoption of the Convention, the implementation of a pipeline project requires the consent only of those states through whose sectors the route passes, provided that environmental requirements and standards are met. This significantly reduces the ability of other Caspian countries to influence the implementation of such projects.
This creates more favorable conditions for the construction of the Trans-Caspian Gas Pipeline, which would transport gas from Central Asia, primarily Turkmenistan, across the Caspian Sea to Azerbaijan and then through the Southern Gas Corridor to European markets.
For Iran, this means a potential decline in its own energy and transit significance. Turkmen gas, which could use Iranian infrastructure to access global markets, would gain an alternative route bypassing Iranian territory. At a time when Azerbaijan, Turkey, and Central Asian states are actively promoting alternative transport and energy corridor systems, Iran faces the challenge of growing isolation.
The ratification of the Convention alone does not automatically mean that the project will be implemented. Its prospects will depend on commercial, investment, and political factors. However, it removes one of the key arguments that has been used for many years against the construction of the pipeline.
Energy projects are developing alongside transport initiatives.
These include, above all, the emerging Middle Corridor between Central Asia and Europe, the development of Azerbaijan’s transport infrastructure, as well as the communication through Armenia known as the “Trump Route.”
In Tehran, these projects are viewed as elements of a single system connecting Central Asia with Turkey and Europe without Iran’s participation.
As a result, Iran risks losing its position as a natural bridge between Central Asia, the South Caucasus, and the Middle East.
The struggle for agency in a changing region
Iran’s decision-making system is multilayered, and the final word remains with supervisory institutions operating within the orbit of the Supreme Leader.
By ratifying the Convention, Tehran could gain certain advantages, including legal certainty regarding the Caspian Sea and the preservation of its partnership with Moscow, which is pushing for the issue to be resolved. At the same time, the potential costs for Iran appear more significant.
It cannot be ruled out that Iran will use institutional barriers and procedural delays to slow down the process. The document could become stuck during approval by higher bodies under the pretext of “protecting national interests.” This would allow Tehran to preserve its negotiating leverage and avoid domestic disagreements. However, the military confrontation with Israel and the United States, increasing sanctions pressure, and the acceleration of alternative routes are gradually reducing the room for a delaying strategy.
More broadly, the ratification of the Caspian Convention is tied to Iran’s system of governance, where regime stability, security, and sovereignty concerns outweigh any short-term benefits.
Iran seeks to become a direct participant in the emerging new transport and energy architecture. However, its key elements are taking shape without Tehran playing a leading role. In the north, this architecture is being formed through the Middle Corridor and the transport infrastructure of the South Caucasus, while in the west it is developing through the future “Development Road” project via Iraq, which is expected to connect the Persian Gulf with Turkey and European markets. This architecture is developing around Iran — but without its participation.
The article was originally published on CivilNet.