To the East of the Caspian Sea begins Central Asia, the western part of the former Turkestan. The Russians and Iranians are joining forces to dominate the Caspian Basin and open a North-South corridor intended to compete with the Suez route. Allied with Azerbaijan, which stands at the crossroads of the North-South and East-West axes, the Turks are striving to gain access to the Caspian Sea in order to develop a pan-Turanian policy in Turkestan. The Chinese are extending their new “Silk Roads” through the area toward the Mediterranean and Europe. No matter. European states are struggling to agree on their Eastern policy, while the Trump administration dreams of withdrawing from the world. The Caspian Sea can wait, at the risk of destabilizing Euro-Asian and global balances.
The Caspian Sea is an inland sea bordered by Azerbaijan and Russia to the West, Kazakhstan to the North, Uzbekistan and Turkmenistan to the East, and Iran to the South. It stretches nearly 1,300 kilometers from North to South and 300 kilometers from East to West. The level of the Caspian Sea (approximately 28 meters below sea level) and its surface area (373,000 sq km) fluctuate depending on the climate and the water input from the Volga River. Over the 20th Century, these measures decreased, stabilized in the 1980s, rose again in the following decade — threatening human installations in the northern part of the basin — and then declined once more over the past eighteen years, according to a report by the Kazakh Parliament (“The time has come to put an end to the economic disaster”, AFP, April 2, 2025).
A Former “Russian Lake”
In Antiquity, the Caspian Sea was known as the “Hyrcanian Sea,” named after a province of Media; the current name refers to the Kassites, an ancient people who lived to the Southwest of this sea. During the Middle Ages, the Caspian Sea and its surrounding regions were incorporated into various successive Turco-Mongol empires, which later fragmented into smaller khanates. Under Ivan the Terrible, the Russians captured Astrakhan at the estuary of the Volga (1556), and the conquest of the Kazakh steppes began in the following century, later extended to Western Turkestan in the 19th Century. The Caspian Sea then became a “Russian lake,” while the Persian Empire along the Southern shore was marginalized. Under the treaties of Gulistan (1813) and Turkmenchay (1828), Persia was forbidden from deploying a war fleet in the Caspian Sea, a right reserved for Russia.
The legal status of the Caspian Sea evolved through the Soviet-Iranian treaties of 1921 and 1940: Iran was allowed to maintain its fleet, and the Caspian Sea was jointly exploited by the USSR and Iran on an equal basis (the 1940 treaty defined the Caspian as “a Soviet and Iranian sea”). The collapse of the USSR and the emergence of new independent states along the shores (Azerbaijan, Kazakhstan, Turkmenistan) disrupted the geopolitical situation, further complicated by the discovery of new oil and gas deposits (6–10% of global resources), raising issues about their exploitation and export to consumption areas. It was at this point that the Caspian Basin re-entered Western geopolitical considerations.
As early as the 1990s, free access to the Caspian Basin, the construction of new pipelines (oil and gas), and the evacuation of the region’s energy resources without transiting through Russian territory became major geopolitical stakes and sources of confrontation between Russia and the West. The United States launched a “Silk Road Strategy,” and the European Union, through the (Technical Assistance to the Commonwealth of Independent States, TACIS) program, funded regional infrastructure projects. Although the rhetoric differed on the other side of the Atlantic (less emphatic and more technical in Europe), the underlying logic and geoeconomic strategies were similar.
It then became clear that the status of the Caspian (sea or lake?) and its legal regime conditioned the development of resources, placing them at the center of geopolitical debates: each riparian state adopted the legal position that best suited its interests. Broadly, the “lake” status mandated collective exploitation; the “sea” status implied the delimitation of territorial waters and exclusive zones. States with smaller maritime openings or poorer offshore hydrocarbon reserves favored the “lake” status. Such was the case for Russia and Iran, opposed by Azerbaijan and Kazakhstan, with Turkmenistan adopting a midlle position. Russia’s stance later evolved, leading to delimitation agreements with Azerbaijan and Kazakhstan, though no global solution emerged quickly (see, for instance, the failure of the Astana Caspian Summit, July 13, 2016).
The conflict also extended to the regulation of underwater pipelines. Unlike Azerbaijan, Kazakhstan, and Turkmenistan, Russia argued that constructing pipelines required the consent of all riparian states. Moscow sought to maintain the advantage provided by the Soviet-era pipeline network centered on Russia, serving as the transit country for Caspian exports. Thus, existing pipelines from Turkmenistan and Kazakhstan bypass the Caspian through the North to reach Novorossiysk on the Black Sea. Turkmen gas follows the same circum-Caspian route, flowing through Ukrainian pipelines toward European markets.
“Back in the USSR”?
To reinforce their energy positions in Europe, Russian leaders consistently opposed the development of a “southern corridor” to the Caspian Sea through Turkey (the “trans-Eurasian bridge”). This “Western route” had opened in the mid-2000s with the construction of the Baku-Tbilisi-Ceyhan (BTC) oil pipeline and the Baku-Tbilisi-Erzurum (BTE) gas pipeline. Against the pan-European Nabucco project, Russia proposed the South Stream project to secure permanent control over westward hydrocarbon exports from the Caspian Basin.
Both projects were shelved by the mid2010s. However, the Turkish-Russian rapprochement that followed the Western retreat from Syria enabled the construction of Turkish Stream, partially aligned with the South Stream logic (without true compensation). The Western governments’ abandonment of the Nabucco gas pipeline project signified their declining interest in the Caspian Sea and Central Asia, leaving these regions to the influence of Beijing and Moscow, which oversee the Shanghai Cooperation Organization (SCO) — an organization that has continuously expanded since it was set up in 2001. It is as if Americans and Europeans have renounced any grand Eurasian strategy.
Militarily, Russia’s Caspian fleet, undergoing modernization, surpasses those of the other riparian states, none of which contest this reality. On October 7, 2015, the launch of Russian Kalibr cruise missiles into Syria from the Caspian Sea drew experts’ attention to the fleet: the frigate “Dagestan” and three Buyan-class corvettes, stationed in the Caspian Sea, fired a salvo of 26 cruise missiles over Irani and Iraq before striking their targets. The Caspian Sea also served as a corridor for Russian bombers operating over Syria via Iranian airspace (including temporary use of the Hamedan airbase in Northwestern Iran). Tehran’s authorization of these movements highlighted the Russo-Iranian alliance in the Syrian-Iraqi theater and beyond, despite tensions and contradictions: Russian bombings from Hamedan ceased in August 2016 after protests from parts of the Iranian political class and Saudi Arabia.
Moreover, Vladimir Putin supported Iran’s admission into the Shanghai Cooperation Organization, supposedly to dilute China’s power within the SCO. Conversely, the vague Russo-Iranian plan to build a canal connecting the Caspian Sea to the Persian Gulf — an idea floated in the 2000s to compete with the Suez route — never came to fruition. However, the recent renewal of the Moscow-Tehran pact revives the logic of a North-South corridor through the Iranian landbridge: the Caspian Sea retains its full geoeconomic value. As for the military dimension, the Caspian-based Kalibr missiles have Ukraine and all of Europe within range. Additionally, the Caspian Sea is linked to Northern Russia and the Baltic Sea by the Five Seas Canal, a network of rivers and canals placing Moscow at the center of waterways connecting the White Sea, the Baltic Sea, the Sea of Azov, the Black Sea, and the Caspian Sea. The Volga River forms the main axis of this system, which accounts for over two-thirds of Russia’s river-sea transport (though only partially operational due to insufficient dredging and lock maintenance).
The Caspian: A “Russian Sea”?
In August 2018, the five Caspian riparian states signed a Convention on the Legal Status of the Caspian Sea. After more than twenty years of negotiations, a consensus was reached: the Caspian would be considered a sea for purposes of territorial division and a lake for purposes of its exploitation (particularly fishing and environmental protection). Submarine pipelines may be built if they comply with environmental requirements, even without the consent of all riparian states. However, the Convention prohibits the establishment of foreign military bases in the Caspian, thereby consolidating Russian dominance. Some observers concluded that the Caspian had become a “Russian Sea,” though the reality is more complex, given Iran’s weight and Turkey’s ambitions.
Indeed, Turkish leaders, although lacking direct access to the Caspian Sea, seek to develop economic, cultural, and political ties with the Turkic-speaking countries of Central Asia (Kazakhstan, Uzbekistan, Turkmenistan, Kyrgyzstan). Azerbaijan, also a Turkic-speaking nation, serves as the linchpin of Turkey’s East-West axis and its projected “Turkic world.” After the 2020 Nagorno-Karabakh war, Ankara strengthened its presence in Azerbaijan and sought to open a corridor through Armenia (Zangezur corridor), linking Azerbaijan to its Nakhchivan exclave and then to Turkey. Beyond geostrategic interests, Ankara and Baku are promoting a pan-Turanian project, officially endorsed by the Organization of Turkic States set up in 2009 (formerly the Turkic Council).
Nevertheless, the pan-Turanian dream collides with multiple obstacles: Iran’s opposition to any Turkish-Azerbaijani corridor cutting across its border; Russia’s desire to control the South Caucasus; China’s reluctance to encourage separatism among its Turkic-speaking minorities, particularly the Uyghurs; and the fact that Turkic-speaking countries in Central Asia — though culturally close to Turkey — maintain political and security ties with Moscow and Beijing, notably through the SCO and the Collective Security Treaty Organization (CSTO).
At the same time, Beijing is extending its new “Silk Roads” through Central Asia, where massive Chinese investments are redrawing the economic and geopolitical map. The Caspian Sea and its surroundings are part of the China-Central Asia-West Asia economic corridor, intended to link China to the Middle East and Europe via Iran and Turkey. Chinese companies are active in Kazakhstan, Uzbekistan, and Turkmenistan, financing transportation, energy, and communication infrastructure, gaining access to raw materials and energy resources, and establishing logistical bases. This Chinese push is not without generating fears among Central Asian states, wary of a new dependency.
Meanwhile, Western powers, focused on immediate crises or domestic issues, seem to have forgotten Central Asia and the Caspian Sea. The withdrawal from Afghanistan, orchestrated by the Biden administration in 2021, signaled the end of an American presence in the region. Europe, preoccupied with its internal challenges and the Russian threat on its eastern borders, is struggling to develop a coherent Eurasian policy. As for the EU’s “Global Gateway” initiative, intended to rival China’s Belt and Road Initiative (BRI), it remains largely at the project stage, with little concrete impact on the ground.
Thus, in the geopolitical competition reshaping Eurasia, the West risks becoming a spectator rather than an actor. The Caspian, a forgotten sea? Perhaps. But this sea, at the heart of Eurasian balances, could become a major geopolitical issue once again if the conflict between Russia and the West were to escalate.
Associate professor of history and geography and researcher at the French Institute of Geopolitics (University of Paris VIII). Author of several books, he works within the Thomas More Institute on geopolitical and defense issues in Europe. His research areas cover the Baltic-Black Sea region, post-Soviet Eurasia, and the Mediterranean.
