The Middle Corridor: How Türkiye Links Central Asia, the Caucasus and Europe by Rail, Road and Sea

Why It Matters

The Middle Corridor is the multimodal route that moves goods between China, Central Asia and Europe across the Caspian Sea, Azerbaijan, Georgia and Türkiye (Turkey) without crossing Russian territory. It matters because governments, shippers and financiers have re-examined east–west trade routes since 2022, and this route is the main non-Russian overland-and-sea option.

Türkiye is its western anchor. Its railways, Black Sea and Mediterranean ports, Bosphorus rail crossing and land border with Bulgaria and Greece connect the Caucasus to European markets. The route is not one line but a chain, and each section is at a different stage of development. This guide separates what exists from what is only proposed, and it avoids unverified volume figures because published numbers differ by source and by method of counting.

Background

What the Middle Corridor Is

The Middle Corridor is a commercial label, not a treaty-based institution. Its formal name in transport circles is the Trans-Caspian International Transport Route (TITR). A route association of rail operators and ports, headquartered in Astana, promotes it.

A typical rail-and-sea itinerary looks like this:

1. Goods enter Kazakhstan by rail from China, or start in Kazakhstan, Uzbekistan, Kyrgyzstan or Turkmenistan.
2. They cross the Caspian Sea by ferry or ro-ro vessel from ports such as Aktau and Kuryk (Kazakhstan) or Turkmenbashi (Turkmenistan) to Baku's port at Alat (Azerbaijan).
3. They continue by rail or road across Azerbaijan to Georgia.
4. In Georgia they either exit through Black Sea ports (Poti, Batumi, Kulevi) or continue by rail to Türkiye via Baku–Tbilisi–Kars.
5. In Türkiye they reach Anatolian and Thracian rail and road networks, Marmaray (the undersea rail tunnel beneath the Bosphorus, opened in 2013), Mediterranean and Aegean ports, and the land border with Bulgaria and Greece.

Chinese policy documents describe a related concept, the China–Central Asia–West Asia Economic Corridor, as one of the Belt and Road Initiative's economic corridors. China–Europe rail services themselves are usually grouped into northern, middle and southern routes.

Infrastructure That Exists

Segment	Status	Key facts
Baku–Tbilisi–Kars (BTK) railway	Operating	Agreement signed 2007; opened 30 October 2017; roughly 830 km in total. A gauge change at Akhalkalaki (Georgia) is needed because the Caucasus network uses 1,520 mm gauge and Türkiye uses 1,435 mm standard gauge
Marmaray rail tunnel	Operating	Opened 29 October 2013; connects the European and Asian sides of Istanbul. It shares track with commuter services, so scheduling is part of the capacity question
Caspian ports and ferries	Operating, capacity-limited	Aktau, Kuryk, Turkmenbashi and Baku (Alat); vessel availability, scheduling and port handling are the recurring constraints named by operators
Georgian railway and Black Sea ports	Operating, being modernized	Poti, Batumi and Kulevi handle Black Sea access; the main rail line has been modernized with multilateral financing
Turkish ports and logistics hubs	Operating	Mersin, İzmir, Istanbul-area terminals such as Ambarlı, Derince and Samsun, plus the logistics centre at Kars, the BTK terminus
Halkalı–Kapıkule railway (Thrace)	Under construction	Intended to link Istanbul's European side with the Bulgarian border

Proposals Still in Discussion

Several links are proposals or at feasibility and planning stages, and readers should treat them as such:

• Kars–Iğdır–Nakhchivan railway. Türkiye and Azerbaijan have discussed a rail link from eastern Türkiye to the Nakhchivan exclave. Its usefulness depends on onward connection across southern Armenia.
• Armenian territory routes. Azerbaijan has long used the term 'Zangezur corridor' for a transit link between mainland Azerbaijan and Nakhchivan. Armenia's 'Crossroads of Peace' initiative proposes opening regional links under each country's own jurisdiction. At the White House on 8 August 2025, Armenia and Azerbaijan initialed a peace agreement text, and the accompanying declaration referred to a 'Trump Route for International Peace and Prosperity' through southern Armenia. The peace treaty still required signature and ratification at the time of writing.
• Kars–Gyumri railway. A historic line between Kars and Gyumri has been unused since the Türkiye–Armenia land border was closed in 1993. Reopening it is a normalization question, not an engineering one.
• Anaklia deep-sea port (Georgia). Georgia has pursued a Black Sea deep-water port at Anaklia, and the project's contractual and financing arrangements have changed more than once.
• China–Kyrgyzstan–Uzbekistan railway. An intergovernmental agreement was signed in Beijing in June 2024. It would create a new southern feeder for Central Asia–West Asia flows.
• Trans-Afghan railway. In July 2025 Uzbekistan, Afghanistan and Pakistan signed a framework agreement for a feasibility process. It is a long-term concept, not an operating link.
• Iraq 'Development Road'. Iraq, Türkiye and Gulf partners have discussed a rail-and-road link from Iraq's Grand Faw port toward Türkiye. It is a parallel north–south corridor, not part of the Caspian route.
• Digital and energy links. Trans-Caspian fibre-optic and electricity links are under discussion. The 2018 Convention on the Legal Status of the Caspian Sea (signed in Aktau by Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan) is the legal backdrop for any seabed infrastructure.

Timeline

Date	Event
1993	Türkiye closes its land border with Armenia after the Kelbajar offensive; UN Security Council Resolution 822 calls for withdrawal of occupying forces
2007	Azerbaijan, Georgia and Türkiye sign the BTK railway agreement; construction begins
3 Oct 2009	Turkic Council founded under the Nakhchivan Agreement
29 Oct 2013	Marmaray opens in Istanbul
Nov 2015	Türkiye and China sign a memorandum on aligning the Middle Corridor with the Belt and Road Initiative (G20, Antalya)
30 Oct 2017	BTK railway formally opened
12 Aug 2018	Caspian Sea legal status convention signed
10 Nov 2020	Armenia, Azerbaijan and Russia sign a trilateral statement ending the 2020 war; one clause concerns transport links to Nakhchivan
15 Jun 2021	Shusha Declaration on allied relations between Türkiye and Azerbaijan
12 Nov 2021	Turkic Council renamed the Organization of Turkic States (OTS); 'Turkic World Vision 2040' adopted
14 Jan 2022	Special Representatives Serdar Kılıç (Türkiye) and Ruben Rubinyan (Armenia) begin normalization talks
Jan 2024	EU hosts a Global Gateway transport corridors investors forum in Brussels
8 Aug 2025	Armenia–Azerbaijan peace agreement text initialed in Washington

The Bottlenecks Operators Describe

The route is slower to scale than a single-line map suggests, for reasons that are practical rather than political:

• Multiple handovers. Cargo may change mode or operator several times across four to six jurisdictions.
• Gauge and equipment changes. The 1,520 mm to 1,435 mm break at Akhalkalaki, and transshipment at Caspian ports, add time and cost.
• Caspian shipping. Vessel numbers, port handling and weather affect scheduling.
• Tariffs and customs. Coordinated through-tariffs and digital document exchange are still being negotiated among the states and operators.
• Competition from other routes. The Northern Corridor via Russia and Belarus, the sea route, and the International North–South Transport Corridor remain alternatives, and shippers choose by cost, time and risk.

For wider context, see the analysis of Türkiye as an energy hub: pipelines, corridors and transit routes from our sister publication Doctrine Review.

Key Players & Positions

Azerbaijan

Azerbaijan is the corridor's central link. Its government presents the country as a transport and energy hub. It has invested in the Baku port at Alat, the Azerbaijani section of BTK and Caspian shipping. President Ilham Aliyev has repeatedly called for unimpeded transit between mainland Azerbaijan and Nakhchivan, and Baku's term for that link is the 'Zangezur corridor'. The 10 November 2020 trilateral statement is the document Baku cites for transport links.

Armenia

Armenia's government has said it is open to opening regional transport links, including with Türkiye and Azerbaijan, provided they respect Armenia's sovereignty, jurisdiction, equality and reciprocity. This is the logic of its 'Crossroads of Peace' initiative. Yerevan rejects the idea of an extraterritorial corridor, and the August 2025 Washington declaration was presented in this light, with a route running through Armenian territory under Armenian law. Armenian officials have also said that opening the border with Türkiye would benefit Armenia's own trade options.

Georgia

Georgia is the geographic hinge between the Caspian and the Black Sea. Its government describes the country as a transit state, which is reflected in modernization of the main railway and in ports such as Poti and Batumi. Georgia also hosts the Akhalkalaki transfer point on BTK. Its Anaklia port project has had a complicated contractual history.

Kazakhstan, Uzbekistan and Central Asia

Kazakhstan, the largest transit state east of the Caspian, has made Caspian ports and rail connections a stated national transport priority. Uzbekistan and Kyrgyzstan stress route diversification, including the China–Kyrgyzstan–Uzbekistan railway and, for Uzbekistan, the Trans-Afghan concept. Central Asian governments generally describe their policy as multi-vector, meaning they use several routes at once and do not treat the Middle Corridor as an exclusive choice.

The Organization of Turkic States (OTS)

The OTS was created as the Turkic Council under the 2009 Nakhchivan Agreement and renamed at the Istanbul summit on 12 November 2021. Its members are Azerbaijan, Kazakhstan, Kyrgyzstan, Türkiye and Uzbekistan; Hungary and Turkmenistan hold observer status. Its 'Turkic World Vision 2040' and summit declarations repeatedly name transport connectivity, customs facilitation and digital trade documents as priorities. The OTS is a cooperation platform, not a customs union or a military alliance. Its decisions are political declarations that member states implement through their own agencies.

Russia

Russian officials have said they favour unblocking regional transport links in the South Caucasus, and they point to the provisions of the 10 November 2020 trilateral statement. Moscow's own priority corridors are the International North–South Transport Corridor, developed with Iran and India, and Eurasian Economic Union transit arrangements. Since 2022, sanctions and logistics disruption have pushed some cargo away from routes crossing Russia, which is one reason the Middle Corridor has drawn attention. Russia is also a Caspian littoral state and a party to the 2018 Caspian convention.

China

China treats the Middle Corridor as part of a multi-route Belt and Road strategy. Its official documents emphasize connectivity across several corridors, and it maintains northern, middle and southern rail routes to Europe. Beijing and Ankara signed a 2015 memorandum on aligning the Middle Corridor with the Belt and Road Initiative. China is also building feeder links, such as the planned railway through Kyrgyzstan and Uzbekistan.

The European Union

The EU frames its interest through the Global Gateway strategy and the extension of its Trans-European Transport Network (TEN-T) planning to neighbouring and Central Asian partners. At the January 2024 Global Gateway transport corridors forum in Brussels, the EU and its member states announced multi-billion-euro investment intentions. Its official line stresses sustainability, regulatory alignment and the diversification of supply chains. Pledges and announcements are not disbursements, and individual projects follow their own approval and financing timelines.

Other Actors

Iran is a Caspian littoral state and a competing or complementary route provider via north–south corridors. The United States has taken a diplomatic role in the Armenia–Azerbaijan track, as the August 2025 Washington declaration shows. Gulf states, Pakistan and Afghanistan are involved in southern proposals.

What to Watch

• Signature and ratification of the Armenia–Azerbaijan peace agreement, and any construction timetable for the southern Armenia route.
• Whether the Türkiye–Armenia border opens beyond limited arrangements, and whether the Kars–Gyumri line is reconsidered.
• Caspian vessel capacity, port handling and through-tariff coordination.
• Halkalı–Kapıkule completion and freight scheduling through Istanbul.
• Financing decisions on Anaklia and other Black Sea links.

Türkiye's Strategic Doctrine

Türkiye's Strategic Doctrine: Connectivity and Mediation

• Connectivity is a state strategy, built through treaties. Ankara argues that the Middle Corridor strengthens Türkiye's position as an east–west and north–south crossroads, and Turkish officials from the Presidency and the Ministry of Transport and Infrastructure describe it as a national priority. The BTK railway was built under a trilateral agreement with Azerbaijan and Georgia, and the 2015 memorandum with China shows that Ankara pursues corridor alignment with several partners, not exclusive blocs.
• Partnership with Azerbaijan and the Turkic states is framed as sovereign cooperation. Türkiye and Azerbaijan describe their relationship as 'one nation, two states' and formalized allied ties in the Shusha Declaration of 15 June 2021. Turkish statements at OTS summits stress transport, trade and customs facilitation among sovereign members, together with respect for the territorial integrity of all states along the route.
• Normalization with Armenia is presented as open-ended. According to the Turkish Foreign Ministry and the Presidency, Türkiye supports full normalization with Armenia and has said it is ready to proceed without preconditions. The special-representative process begun on 14 January 2022 and the 2022 understanding on opening the border to third-country nationals and diplomatic passport holders belong to this track. Turkish officials have also said they coordinate with Azerbaijan and welcomed the August 2025 Washington declaration. Ankara's legal reference points are the 1921 Treaty of Kars, which fixed the Türkiye–Armenia border, and its 2005 proposal for a Joint Historical Commission to study the Events of 1915.
• Mediation and impartial rule application support the corridor's credibility. Türkiye applies the 1936 Montreux Convention, including Article 19 restrictions on warships of belligerent states, which Ankara says prevented naval escalation in the Black Sea while commercial passage continued. Its hosting of the 2022 Istanbul talks and its role in the Black Sea Grain Initiative are cited by the Turkish Foreign Ministry as examples of trade-enabling diplomacy.
• Corridors depend on stable borders. Türkiye's doctrine of neutralizing threats at their source, grounded in Article 51 of the UN Charter, is presented by Ankara as part of keeping southern land and sea links secure.

The legal and historical basis is a mix of treaty law (Kars 1921, Lausanne 1923, Montreux 1936, BTK 2007), the OTS founding documents, and the UN Charter. Readers should treat the points above as Ankara's stated positions, which other states may weigh differently.

For the straits regime, see The Turkish Straits and the Black Sea Corridor: How the Montreux Regime Governs Passage in Peace and War. For the Armenia track, see Can the Turkish–Armenian Border Reopen?. For the southern maritime dimension, see The Eastern Mediterranean Corridor. On mediation, see Crossroads Review on Türkiye's mediation in the Russia–Ukraine War and the Black Sea Grain Initiative, and Bloc Politics on Türkiye as a bridge between blocs.

Source Comparison

Commentary on the Middle Corridor often mixes three questions: whether it is a commercial route, a geopolitical alternative to Russia, and a vehicle for a Turkic political bloc. Official sources tend to answer the first and avoid the others, while analysts and media often press the second and third.

Question	Common international framing	Turkish and regional primary sources	Reading note
Is it an alternative to Russian routes?	Often described as a sanctions-era bypass	Transit-state governments describe it as diversification, not exclusion; Türkiye says it is open to several partners	Both can be true: diversification is the stated aim, and the effect on Russia-bound traffic is a market outcome
Is the OTS a political bloc?	Sometimes described as a 'Turkic bloc' or a vehicle for Turkish influence	OTS documents describe a cooperation platform of sovereign members, with transport and trade as core themes	The OTS has no binding customs, defence or supranational powers
Armenia route naming	'Zangezur corridor' (Azerbaijan), 'Crossroads of Peace' (Armenia), 'Trump Route' (Aug 2025 declaration)	Baku emphasizes unimpeded transit; Yerevan emphasizes sovereignty and reciprocity	The naming signals different legal expectations; the route is still a proposal
Türkiye–Armenia border	Frequently framed as linked to the Armenia–Azerbaijan peace track	Ankara says it seeks normalization without preconditions while coordinating with Baku	Both statements appear in official remarks, which is why the pace of normalization stays contested
Capacity and volumes	Headline figures vary widely between reports	Official targets exist but are not treated here as results	Compare units (tonnes, TEU, trains) and whether figures count transit or total cargo

A second source gap concerns time and cost claims. Operators, ministries, consultancies and international financial institutions publish transit times and cost comparisons built on different assumptions about sea, rail and border waiting times, so the same corridor can look fast or slow depending on the source. Our approach is described in the Editorial Principles.

On Black Sea passage rules, which affect the corridor's western exit, see Fact Check: Can Türkiye Close the Straits to Anyone It Wants?.

Key Terms & Related Guides

• Middle Corridor / TITR. A commercial label for the Trans-Caspian route between China or Central Asia and Europe via Azerbaijan, Georgia and Türkiye.
• BTK (Baku–Tbilisi–Kars). The railway completed in 2017. It requires a gauge change at Akhalkalaki in Georgia.
• Gauge. The distance between rails. The Caucasus and Central Asia mostly use 1,520 mm, while Türkiye and most of Europe use 1,435 mm.
• TEU. Twenty-foot equivalent unit, a container measurement. Always check whether a source reports TEU, tonnes or train counts.
• Zangezur corridor / Crossroads of Peace / 'Trump Route'. Different names for proposed links through southern Armenia. They describe different legal concepts, and none is an operating route yet.
• OTS. The Organization of Turkic States, a cooperation platform of Azerbaijan, Kazakhstan, Kyrgyzstan, Türkiye and Uzbekistan, with Hungary and Turkmenistan as observers.
• International North–South Transport Corridor (INSTC). A Russia–Iran–India route and a different project from the Middle Corridor.
• Global Gateway. The EU's external investment strategy, which includes transport corridor financing.
• Montreux Convention. The 1936 regime governing passage through the Turkish Straits, which ensures free commercial transit in peacetime.

Related guides: Editorial Principles explains how sources are weighed. The Turkish Straits and the Black Sea Corridor, Can the Turkish–Armenian Border Reopen?, and The Eastern Mediterranean Corridor cover the adjacent corridors. For the legal side of Black Sea diplomacy, see Frontline Diplomacy's fact check on Türkiye and the Black Sea Grain Initiative.

Perspective Note

The Strategic Corridor presents Türkiye's official perspective and legal position as a distinct analytical viewpoint, while clearly distinguishing it from opposing claims. Wherever possible, assertions are attributed to primary sources such as treaties, UN and UNESCO documents, court rulings and archival records. This article was prepared by The Strategic Corridor Editorial Team.