2026年6月5日、内田州特任研究員が、第11回ウランバートル対話第2日のパネル"Connectivity Between Northeast and Central Asia"に登壇し、講演"Connecting the Two Ends of Eurasia: The Trans-Caspian Corridor and Implications for the South Caucasus, Mongolia, and Japan"を行った上で、パネルディスカッションで登壇者および会場からの質問に答えました。

以下に、この講演のために事前提出されたペーパーを掲載します。

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Connecting the Two Ends of Eurasia:
The Trans-Caspian Corridor and Implications for the South Caucasus, Mongolia, and Japan

Shu Uchida
Project Researcher, Research Center for Advanced Science and Technology (RCAST), University of Tokyo

Abstract: The geopolitical crisis of 2022 accelerated a structural rerouting of Eurasian trade, elevating the Trans-Caspian International Transport Route (TITR), or Middle Corridor, as a strategic alternative connecting East Asia to Europe via Kazakhstan, the Caspian Sea, Azerbaijan, Georgia, and Türkiye. This paper examines the TITR from two angles: Japan's growing engagement with continental Eurasian connectivity — reflecting an imperative to diversify supply chains beyond the maritime Indo-Pacific — and the South Caucasus as an indispensable interface enabling the corridor to function as a transcontinental route. The paper further considers implications for Mongolia as a landlocked state seeking strategic value within Eurasian networks.

Keywords: TITR, Middle Corridor, Trans-Caspian, Japan, South Caucasus, supply chain resilience, Eurasian connectivity, Azerbaijan, Georgia

Introduction
The architecture of Eurasian connectivity is being reconfigured. For decades, overland trade between East Asia and Europe relied predominantly on the Trans-Siberian Railway running through Russian territory. Maritime routes through the Suez Canal served as the primary arteries of global commerce. Both options, however, have been subject to increasing disruption: The geopolitical crises of recent years have rendered the Northern Corridor politically and commercially untenable for many shippers, while maritime chokepoints remain vulnerable to conflicts, insurance surcharges, and geopolitical leverage.

Into this environment, the Trans-Caspian International Transport Route (TITR) — also referred to as the Middle Corridor — has attracted renewed and serious attention. The route links China and East Asia to Europe through Kazakhstan, a Caspian Sea crossing, Azerbaijan, Georgia, and onward to Türkiye or the Black Sea. It is a multimodal corridor, combining rail, maritime, and road segments, and its operation requires coordination among customs authorities, port operators, railway companies, and logistics providers across multiple sovereign states.

This paper proceeds in three analytical steps. First, it examines why Japan — an island state long defined by its maritime orientation — has developed a strategic interest in a continental overland corridor. Second, it analyses the South Caucasus not as a passive transit zone, but as an active and indispensable interface within the TITR architecture. Third, it considers the implications of this analysis for Mongolia, a landlocked state that faces analogous structural challenges and for which the South Caucasus experience may offer a useful, if partial, reference point.

Japan and the TITR: From Maritime Power to Continental Engagement
Japan's engagement with the TITR represents a significant dimension of its evolving foreign economic policy. Japan is not a continental power in the traditional sense. Its economic model has historically depended on stable sea lanes, imported energy, and maritime supply chains connecting it to global markets. The Free and Open Indo-Pacific (FOIP) vision, which has guided Japanese foreign policy since 2016, is fundamentally maritime in its framing.

Yet, Japan has increasingly recognised that a purely maritime orientation leaves it exposed. The COVID-19 pandemic demonstrated the fragility of just-in-time supply chains. The geopolitical crisis in 2022 disrupted not only the Northern Corridor but also air routes over Russian territory that Japanese carriers had long relied upon for Europe connections. These disruptions have created a strategic case for diversification that goes beyond any single sector or region.

Japan's engagement with the TITR was formalised at the first Summit of the "Central Asia plus Japan" Dialogue (CA+JAD), held in Tokyo in December 2025. The Summit's Tokyo Declaration explicitly identified Central Asia's role as a "junction between Europe and Asia" and committed Japan to supporting the further development of the TITR. This political framing is significant: it signals that Japan views the Middle Corridor not merely as a logistics project but as a structural element of a more resilient and diversified Eurasian connectivity architecture.

The data support this strategic turn. Japanese and South Korean cargo has increasingly been routed through the TITR using Container Rail Express (CRE) services connecting East Asia and Europe. In early 2025, Japanese cargo was successfully transported through the corridor on a trial basis, demonstrating its operational feasibility. According to the TITR Association, cargo volumes transported through Kazakh and Azerbaijani ports reached approximately 3.3 million tons in 2024, a 20 percent increase from the previous year, while container traffic reached 56,500 TEU — a 176 percent increase year-on-year. The World Bank's 2030 Middle Corridor Action Plan projects that full implementation of planned investments could halve transit times and triple freight volumes by the end of the decade.

For Japan, the TITR offers three distinct strategic benefits. First, diversification: it provides an additional continental option connecting Japan and East Asia with Europe and Central Asia, reducing dependence on any single route. Second, resilience: the existence of an alternative route creates redundancy in the system, protecting against disruption to maritime or northern land routes. Third, continental engagement: the TITR enables Japan to extend its strategic presence into Eurasia through infrastructure partnership, logistics cooperation, and investment — without requiring a confrontational posture. It should be noted that the TITR remains more costly than maritime alternatives, with freight rates running significantly higher than Suez Canal routes; yet for time-sensitive cargo, supply chain diversification, and geopolitically motivated rerouting, this cost premium is increasingly accepted as a strategic investment rather than a commercial inefficiency.

This last point deserves emphasis. Japan's approach to TITR engagement is deliberately calibrated. The language used in official documents emphasises connectivity, resilience, and stable supply chains rather than geopolitical competition. This framing allows Japan to work cooperatively with Central Asian states, South Caucasus states, Türkiye, and European partners, while avoiding the zero-sum logic that might otherwise constrain its options.

The South Caucasus as Interface: Beyond Transit
If Japan's engagement illustrates the demand side of the TITR's growing importance, the South Caucasus illustrates the indispensable structural role that a geographically compact and politically complex region plays in enabling the corridor to function.

After goods cross Central Asia and traverse the Caspian Sea, they reach Azerbaijan, from where the route continues through Georgia toward Türkiye and the Black Sea. This geography is not incidental. The South Caucasus occupies a narrow but structurally critical space between the Caspian and the Black Sea — the only viable overland link between Central Asia and Europe that does not pass through Russia or Iran.

The region hosts the key infrastructure nodes of the corridor: the Baku-Tbilisi-Kars (BTK) railway, which operationalised the rail link between Azerbaijan, Georgia, and Türkiye; the Baku-Alyat port complex on the Caspian Sea, which serves as the primary gateway from Kazakhstan; Georgian railway networks connecting to Black Sea ports at Batumi and Poti; and the BTC oil and BTE gas pipelines, which established an earlier but analogous logic of South Caucasus connectivity. Taken together, these elements constitute not merely a transit zone but what this paper terms a connectivity space — a region whose strategic value lies in its capacity to link adjacent zones that would otherwise be disconnected.

The South Caucasus is also, of course, a region of considerable political complexity. Georgia has pursued European Union (EU) association and is currently navigating a contested political environment. Armenia and Azerbaijan concluded a devastating war over Nagorno-Karabakh, and peace negotiations remain fragile. Russia, Türkiye, Iran, and the EU all maintain competing interests in the region. The result is a layered geopolitical environment in which infrastructure and politics interact in real time.

This complexity, however, does not diminish the region's importance — it amplifies it. Eurasian connectivity does not depend only on physical infrastructure. It depends on whether difficult regions can remain open, functional, and reliable. The South Caucasus demonstrates, imperfectly but instructively, that a geographically constrained region with contested politics can nevertheless serve as a systemic enabler of wider integration, provided that sufficient institutional coordination, investment, and political stability are maintained.

It is worth noting that the analytical question for the TITR is not which individual state within the South Caucasus matters most. Such framing risks encouraging zero-sum competition and misses the systemic logic of the corridor. The South Caucasus functions as an interface precisely because multiple states — Azerbaijan, Georgia, and potentially, in the future, Armenia — together provide the redundancy, infrastructure, and territorial continuity that the route requires. A peace process between Armenia and Azerbaijan may over time diversify the routing options within the region; this would not reduce the South Caucasus's importance but confirm it by expanding its connectivity potential.

Transit time reductions further underscore this systemic importance. Compared to maritime routes, transit times have been reduced from 38–53 days to 18–23 days between East Asia and Europe according to the TITR International Association and EY Kazakhstan (2024). This improvement reflects investments across the entire corridor, but the South Caucasus segment has been particularly important given its historical bottlenecks in port capacity and customs processing.

Implications for Mongolia
Mongolia occupies a structural position that is in some respects analogous to, and in others quite different from, that of the South Caucasus. Like the South Caucasus states, Mongolia is a geographically constrained state located between major powers — in Mongolia's case, Russia and China — that must think carefully about connectivity, transit options, and economic resilience. Unlike the South Caucasus, Mongolia is not currently part of the TITR's operational network in a direct sense.

The relevance of the TITR for Mongolia is therefore not primarily operational but conceptual and strategic. The experience of the South Caucasus offers Mongolia a reference point for understanding how geographically constrained regions can increase their strategic value within wider Eurasian connectivity networks. The lesson is not to copy the South Caucasus model — the geographic and political contexts are sufficiently different to preclude direct replication. The lesson is rather that transit spaces can acquire significant strategic value when they offer reliable, diversified, and well-managed routes connecting adjacent regions; and that this value depends not only on physical infrastructure but on institutional coordination, customs modernisation, investment climate, and political stability.

Mongolia's "Steppe Road" policy and its integration with China's Belt and Road Initiative suggest an awareness of this opportunity. This reflects the growing recognition that Mongolia's geographic position, while challenging, can be transformed into a strategic asset if the right investments and institutional frameworks are put in place.

Conclusion
The TITR is no longer a political aspiration. It is an increasingly operational and strategically significant Eurasian connectivity space, whose growth is driven by geopolitical disruption, institutional investment, and the structural demand for diversified trade routes. Japan's growing engagement with the corridor reflects a deliberate strategic evolution, extending its connectivity interests from the maritime Indo-Pacific to the continental Eurasian space. The South Caucasus, meanwhile, functions not merely as a transit region but as an indispensable interface within a wider Eurasian connectivity space. Its significance lies not in the dominance of any single state, but in its capacity to sustain linkages between Central Asia, the Black Sea region, Türkiye, and Europe.

The broader insight this analysis offers is a relational one: the future of Eurasian connectivity will not be determined by the dominance of any single country or route. Rather, it will depend on whether multiple connectivity spaces remain linked, open, and functional. The TITR illustrates how infrastructure, institutions, and geography can together create resilient connections across Eurasia. For Mongolia, and for other geographically constrained states seeking strategic relevance in a reconfiguring Eurasian order, this insight carries both practical and strategic significance.