By Glen E Howard
Published 12 August 2026 10:38 pm BST
Russia has quietly established a new strategic supply route to Iran across the Caspian Sea. Called by some the Caspian Express, this logistics corridor has become the backbone of Vladimir Putin’s effort to arm Tehran while allowing both countries to circumvent US maritime pressure in the Persian Gulf.
Moscow applied this model during the Syrian civil war when it sustained the regime of Bashar al-Assad through a maritime supply route sometimes termed the Syrian Express.
Operating for nearly a decade between occupied Crimea and the Syrian port of Tartus, the supply corridor allowed Moscow to reinforce its expeditionary forces despite Western sanctions and diplomatic pressure. Turkey closed the Bosphorus to warships following the 2022 invasion of Ukraine, squeezing the route, before the lifeline was cut by the end of the Syrian regime in 2024.
Today, Russia has replicated that approach in the Caspian, transforming the inland sea into its logistical backbone for its military partnership with Iran. The strategic consequences are becoming increasingly visible as “Gulf War III” expands to the region.
Earlier this year Israel carried out air strikes against Iran’s Caspian naval base at Bandar Anzali, destroying port facilities and several boats in the first ever use of Israeli air power in the Caspian region. At the end of July, Ukraine carried out a drone strike on an Iranian commercial vessel, killing one sailor in the Caspian, which prompted Tehran to consider retaliatory strikes against the Ukrainian port of Odesa. Since Putin extended Russia’s aggression against Ukraine in 2022, Iran has become a vital Russian ally – supplying Moscow with $2.7bn in ballistic and air-defence missiles, including hundreds of Fath-360 short-range ballistic missiles and 200 surface-to-air missiles, while Russia has spent more than $4bn on Iranian military equipment since late 2021.
Iran provided the key components and technology for Putin’s fleet of Shahed drones and helped Moscow establish production facilities at the Alabuga Special Economic Zone to manufacture up to 6,000 units a year. As many as four Iranian Caspian ports are working around the clock to import wheat, feed and oil as Tehran reroutes essential trade through the inland sea due to the American blockade of the Strait of Hormuz.
Meanwhile, in the northern Caspian, the Russian port of Olya has become Moscow’s primary transit hub for importing Iranian drone components and ammunition. Consequently, both Russia and Iran rely on the landlocked Caspian as an indispensable supply line for their respective war efforts.
In a striking historical irony, this same “Persian Corridor” across the Caspian once served as a vital lifeline during World War II, when massive quantities of American Lend-Lease assistance flowed through Persia to sustain the Soviet war effort against Nazi Germany.
Today, Moscow is once again relying on this historic corridor, confident that the Caspian remains an untouchable sanctuary. For decades, Russia has treated the Caspian Sea as a protected “bastion” beyond Western reach, where its naval forces launched Kalibr cruise missiles against Syria in 2015, and more recently against Ukraine from its missile range at Kapustin Yar using Putin’s new Wunderwaffe weapon – the Oreshnik ballistic missile.
Because the Caspian is landlocked, the United States can do nothing as a maritime power to prevent Russia from shipping Iran supplies that would otherwise pass through the Strait of Hormuz, now blockaded by the US Navy.
This geographic reality plays directly into Moscow’s broader geopolitical ambitions as the Caspian becomes the centrepiece of a North-South transport corridor linking Russia, Azerbaijan, Iran and ultimately India while bypassing maritime chokepoints controlled by the West. In doing so, Moscow and Tehran are operationalising Sir Halford Mackinder’s Heartland theory by creating a landlocked Eurasian logistics network that blunts Western sea power.
Interdicting these supply lines has therefore taken on greater urgency as Moscow has actively rebuilt Iran’s offensive capabilities during recent pauses in fighting with the US in the Gulf. American officials told The New York Times that Russia helped Iran restock after it lost 60 per cent of its drone arsenal during the war.
As the regional dimension of the Iran-US conflict expands, the Trump administration must decide whether to contest the Caspian Express before it becomes the permanent logistical spine of the Russia-Iran partnership.
The White House has already laid the diplomatic foundation by supporting an Armenia-Azerbaijan peace agreement and by launching the Trump Route for International Peace and Prosperity. It should now build on that success by developing a regional strategy that leverages Azerbaijan’s emergence as a rising middle power in the South Caucasus while enabling Ukraine to sustain military pressure on the Caspian Express without risk of direct US involvement.
History shows that wars are often decided not only on the battlefield but along the supply routes that sustain them. The Syrian Express prolonged one war for years. The Caspian Express now underpins the Russia-Iran strategic partnership and Tehran’s effort to outlast the United States in a war that is now going into its sixth month.
Whether the Caspian Express remains Moscow’s strategic lifeline to Iran – or ultimately fails – will depend on if Washington adopts a regional strategy capable of contesting the emergence of a new Persian Corridor and stymieing Russian efforts to arm Iran.
Glen E. Howard is president of The Saratoga Foundation, a US non-profit organisation researching Russia, China, Iran and North Korea and the countries’ interests in the rest of the world.
Full text found here: https://www.telegraph.co.uk/us/comment/2026/08/12/putin-lifeline-iran-threat-trump-blockade/
