Is Russia secretly helping Iran develop advanced supersonic cruise missiles?

Amid escalating tensions in the Middle East, Russia is secretly helping Iran develop advanced supersonic cruise missiles under a multi-year covert programme, according to a media report.

The programme, codenamed C430L, involves some of Russia’s most experienced missile specialists, the Financial Times reported on Tuesday. The daily, which said its investigation was based on leaked Russian correspondence, travel records and an analysis of military patents, described the collaboration as one of the most significant known transfers of strategic military technology from Moscow to Tehran.

According to the report, the C430L programme began in 2023 and continued even during the US-Israeli attacks on Iran this year. It aims to develop a ramjet propulsion system that could enable cruise missiles to travel at several times the speed of sound.

The daily quoted Fabian Hinz, an expert on Iranian missiles and a senior analyst at Conflict Armament Research, as saying that a programme of this scale would require political approval at the highest levels in Russia.

“This is a transfer of highly strategically sensitive military technology from Russia that the Iranians have wanted to acquire for decades,” Hinz said.

The report claimed that Iran has already built and flight-tested a ramjet propulsion system, although there is no evidence that a Russian-assisted supersonic cruise missile has yet been deployed.

The daily further noted that the programme is part of the increasingly close strategic and military ties between Russia and Iran. Tehran supplied Moscow with Shahed attack drones, which have become a key component of Russia’s war effort in Ukraine, and also assisted in setting up their production inside Russia.

The Donald Trump administration has accused both China and Russia of providing military and financial assistance to Tehran as the US-Iran conflict enters its seventh month.

Last month, citing a European government document, NBC News reported that Russia had begun sending military-related supplies to Iran through the Caspian Sea. The shipments reportedly included TNT, drone components and ammunition. Experts who analysed satellite imagery also suggested that the consignments could contain components used in ballistic missile production.

Reports indicated that Moscow opted for the Caspian Sea route because it is difficult for Western naval forces to monitor. Experts believe the Russian supplies could help Tehran replenish parts of its depleted arsenal amid its ongoing conflict with the United States.

A June report by the Middle East Institute said Russia had provided Tehran with satellite targeting data for strikes on US forces and supplied advanced fibre-optic drone technology. It also said that throughout Operation Epic Fury—the US military campaign against Iran—Moscow continued to produce and deliver fighter jets for the Iranian air force and train Iranian pilots.

The cooperation between the two countries has also expanded to intelligence sharing that helps Tehran target the US bases in the Gulf countries, the report claimed.