A Russian military aircraft reportedly flew to Tehran with $US145 million in cash, a British NLAW anti-tank missile, a US Javelin anti-tank missile and a US Stinger anti-aircraft missile.

Those munitions were originally meant for Ukraine, but Russia managed to intercept them, according to Sky News.

Less than a fortnight later, Iran provided Russia with 160 unmanned aerial vehicles (UAVs), which included 100 Shahed 136 drones.

Russia has been accused of using drones to disable critical power and water infrastructure in Ukraine, particularly in the capital Kyiv, by flying the vehicles kamikaze-style into targets. 

In the past week alone, the Kremlin has been accused of damaging 40,000 tonnes of grain, while Russia has accused Kyiv of attacking Moscow.

Why does Iran supply Russia with drones?

Steven Feldstein, writing for the Carnegie Endowment for International Peace, says there are two main factors that explain Iran’s export of drones to Russia. The main selling point for Moscow is the low cost of the UAVs.

The Shahed 136, for example, is estimated to cost a “mere” $US20,000 ($29,889), as opposed to a Kalibr cruise missile, which is said to go for about $US1 million.

The Iranian drones are also immediately available, Mr Feldstein says, unlike several advanced models developed by Russian manufacturers which should eventually carry large payloads, but are far from being produced. 

The UAVs that Russia is currently producing have short ranges and small warheads, making them inferior to similar options from Iran.

In the short term, Mr Feldstein writes, the drones from Iran are filling a gap until the Kremlin can boost its own UAV manufacturing.

But it is uncertain whether Moscow will be able to develop the necessary manufacturing capacity to produce the drones it needs, given the sanctions imposed on it and the ongoing disruption to Russia’s supply chains. 

What kind of drones does Iran make?

According to the United States Institute of Peace (USIP), Iran’s systems range from small, lightweight short-range systems, all the way up to medium and heavy UAVs, which serve different purposes, from intelligence to surveillance and reconnaissance roles. 

The Shahed 136s are kamikaze drones, which means that they are not designed to return to base after they attack. They’re loaded with built-in ammunition and dive towards a target to explode on impact.

The Shahed 136 has the ability to evade radar detection and can operate at a range of up to almost 2,500 kilometres. The downside of this drone is that it flies to a pre-programmed destination and cannot be piloted while in the air. 

These types of kamikaze drones differ from cruise missiles because they are designed to loiter for a relatively long time around the area it targets.

In April research by Conflict Armament Research (CAR) revealed the Shahed 136 drone technology is based on illicitly acquired German technology.

CAR, an organisation based in the UK that investigates weapons components, examined components in 20 Iranian drones and munitions in Ukraine. Half of them were Shahed 136s.

CAR confirmed that the motor in the kamikaze drone was reverse-engineered by an Iranian company that had been sanctioned by the UK, US and EU.

The company that made the drones appeared to have tried to conceal its role in the production of UAVs, with CAR investigators discovering that original serial numbers on components found in Ukraine had been erased in a possible effort to disguise their origin. 

Where are the drones being made?

Iran is providing Russia with materials to build a drone-manufacturing plant east of Moscow as the Kremlin looks to lock in a steady supply of weaponry for its ongoing invasion of Ukraine, according to a US intelligence finding released by the White House.