On September 12, Poland closed its border with Belarus in response to Russia and Belarus’ Zapad 2025 military exercises. Polish Prime Minister Donald Tusk warned that the drills were designed in part to rehearse a strike on the Suwałki Gap, the narrow stretch of territory connecting Poland with Lithuania and lying between Belarus and Russia’s Kaliningrad exclave. Nearly a week after the exercises concluded, the Polish-Belarusian border remains sealed. 

There are three railway and two road crossing points along the border, and their closure deals a fatal blow to the intercontinental land trade between the EU and China. For years, China’s rail freight to Europe has passed through the Brest–Terespol crossing and the Małaszewicze terminal, after transiting Kazakhstan, Russia, and Belarus en route to Poland and beyond. Although Russia’s invasion of Ukraine led to a sharp drop in both the volume and value of goods transiting this route in 2022, traffic rebounded the following year, surpassing pre-war levels. In 2024, this route, also known as the Northern Corridor, accounted for more than 90 percent of EU-China rail trade, generating $200 million in customs duties for Poland. Yet, the main beneficiaries have been Belarus and, to a certain extent, Russia. Both countries utilized the route to circumvent sanctions and facilitate each other's access to strategic goods, thereby powering their economies. China also benefits from the efficient flow of cargo through Poland, as most shipments along the route are westbound, carrying higher-value Chinese exports.

Warsaw’s calculus likely extends beyond security imperatives, encompassing a wider effort at strategic signaling – to reinforce its commitments to partners and to send a clear message to rivals. First of all, Poland shows that security concerns will take precedence over economic interests when the two come into conflict. The move could also sit well with the Trump administration’s recent call for coordinated pressure on Russia and China. Meanwhile, Warsaw may use the blockade to ask China to pressure Moscow to stop its increasingly assertive behavior in Eastern Europe. Yet Russia remains too vital a partner for Beijing to cast aside in return for a trade corridor that accounts for barely 4 percent of EU–China trade. In July, China’s Foreign Minister Wang Yi told the EU’s Kaja Kallas that Beijing cannot accept a Russian defeat in Ukraine, as this could allow the United States to turn its full attention to China. On September 15, Yi was in Poland, co-chairing the Poland-China Intergovernmental Committee meeting with his Polish counterpart, but the border closure issue was not mentioned in the Chinese readouts. 

Even if Warsaw eventually reopens the border, the damage has already been done. Shippers and freight forwarders, faced with uncertainty and mounting costs due to delays, are expected to diversify their routes. This shift will not be easily reversed, as confidence in Poland’s role as a stable gateway has been shaken. Russia’s repeated breaches of Polish and Estonian airspace and the triggering of NATO’s Article 4 twice within a week only deepen the perception of fragility, reinforcing the sense that security risks outweigh economic convenience. 

On the Russian side, the logic of securitization could just as easily shape policy toward rail transit. In October 2024, Moscow introduced a directive prohibiting the transit of dual-use items through its territory, which caused unprecedented delays along the Northern Corridor. Containers with machinery and electronics were blocked and sent back to China. While Beijing’s stricter export controls on dual-use goods have helped ease the issue, growing volatility and rising costs have reduced the corridor’s appeal for East–West trade. At the same time, Russia has been aligning its transport strategy with its foreign policy objectives, that is, focusing on the pivot towards the East. Alongside its recent agreement with Beijing over new gas exports through the planned Power of Siberia 2 pipeline, Moscow has prioritized upgrading its long-dormant rail network in the country’s east, reflecting a broader shift toward deepening trade with China and Belarus rather than relying solely on its role as a transit corridor between China and Europe. 

The securitization of the Northern Corridor is likely to drive cargo toward alternative routes, much as it did in the early stages of Russia’s full-scale invasion of Ukraine. Traditional maritime shipping stands out as the primary option. While cheaper than rail, it comes with significantly longer delivery times. Currently, it accounts for more than 90 percent of the EU-China trade by volume. China may also consider sending its cargo through the Northern Sea Route (NSR), along Russia’s northern coast to Europe. Melting ice and geopolitical shifts driven by climate change in the Arctic raise the odds of the Northern Sea Route developing into a credible alternative for EU-China commerce. In September, Beijing tested an 18-day express route linking its largest port to Felixstowe in the U.K., as part of its larger goal to establish a regular service via Russia’s NSR to connect with multiple ports in Asia and Europe. Yet, natural, infrastructural, and financial barriers prevent the NSR from reaching its full potential in the near future. It leaves us with the Middle Corridor, a land-sea rail route linking China with Europe through Central Asia, South Caucasus, and Türkiye. Poland’s state-controlled rail freight operator, PKP Cargo, said the longer closure of the border with Belarus would divert trade south, through the Trans-Caspian route. 

The Middle Corridor emerged as a viable alternative to the northern route after Russia’s invasion of Ukraine in February 2022. Though limited in capacity, it successfully attracted parts of the cargo diverted from Russian railways in the last three years. During this time, cargo volume has increased more than fivefold – from 840,000 tons in 2021 to 4.5 million tons in 2024. Azerbaijan, Georgia, Türkiye, and Kazakhstan have gone a long way to improve the hard and soft infrastructure capacities of the route. Now, as it stands to gain from the diversion of cargo from the north, four geopolitical changes may further facilitate this process. 

Firstly, gradual progress in Armenia-Azerbaijan normalization, coupled with growing prospects for a peace agreement and Armenia’s warming ties with Türkiye, eliminates a key bottleneck, enhancing the South Caucasus’ potential to serve as a stable corridor for regional and intercontinental trade. This aura of stability may look more appealing to logistics companies amid further disruption of traditional trade routes running through the Middle East and Eastern Europe. Global shipping has recently been slowly reeling from the war in Ukraine and Houthi strikes in the Red Sea. Now, simmering tensions between Russia and NATO on one side, and Iran and Israel on the other, cast additional doubt on the reliability of existing routes, bolstering the relevance of alternatives like the Middle Corridor. 

Second, and relatedly, the Armenia-Azerbaijan agreement to reopen transport connectivity between the two countries will add another leg to the Middle Corridor’s South Caucasus section, complementing existing road and railway routes passing through Georgia. In the Washington Declaration, signed in August by Armenian and Azerbaijani leaders, Armenia agreed to build the Trump Route for International Peace and Prosperity (TRIPP) on its territory – a 43 km railroad that will connect Azerbaijan with its Nakhchivan exclave and Türkiye. As capacity constraints have been one of the key bottlenecks along the Middle Corridor, adding a new line would lessen the pressure and decrease congestion on the route. 

Third, the EU and China have thrown their weight behind the modernization of the Trans-Caspian route, seeking to position it as an important conduit for regional and global supply chains. Brussels announced a 12 billion Euros investment package for Central Asia, targeting transport, critical raw materials, energy, and water management projects. The European Commission’s inaugural Black Sea strategy reaffirmed Brussels’ commitment to the Trans-Caspian corridor, designating it a Global Gateway priority to link the South Caucasus and Central Asia with the EU’s TEN-T network. China signed an agreement with Azerbaijan and Kazakhstan to build an intermodal cargo terminal in Azerbaijan’s Alat port in the Caspian Sea, aiming to increase container train traffic along the China-Europe-China corridor. In August, one of China’s major freight operators, China Railway Container Transport Co., Ltd, joined the Middle Corridor joint venture, which brings together rail operators of Azerbaijan, Georgia, and Kazakhstan to provide a single-window multimodal logistics service. Beijing’s growing involvement in connectivity across the South Caucasus is closely tied to its diplomatic outreach, marked by the conclusion of strategic partnership agreements signed with Armenia, Azerbaijan, and Georgia in the last three years. 

Last but not least, the growing clout of the Organization of Turkic States as a more cohesive bloc of like-minded countries further elevates the Middle Corridor’s role in regional cooperation. In 2024, cargo shipments from Türkiye and Central Asian countries via Azerbaijan totaled 11 million tons. On the one hand, deepening transport cooperation under the OTS is opening new pathways for the Middle Corridor to emerge as a key regional trade artery. On the other hand, coordinated efforts to digitalize customs documentation, integrate data exchange among member states, and reduce bureaucratic friction may improve the corridor’s status as a viable transit link between the EU and China, ready to absorb cargo diverted from the Northern Corridor.

Taken together, Poland’s closure of its border with Belarus creates a rare opportunity for Middle Corridor countries to position themselves as pivotal players in Eurasian connectivity. Yet, the corridor’s advantages should not be taken for granted. Azerbaijan, Georgia, and Kazakhstan need to ensure that the route does not become part of the zero-sum “connectivity wars” between regional and global powers. At the same time, sustained investment in infrastructure and governance reforms will be critical to translating geopolitical momentum into lasting commercial value. If managed wisely, these windows of opportunity could help transform the Middle Corridor from being a backup route in times of crisis to a durable pillar of Eurasia’s transport architecture.