According to sources knowledgeable about the situation in Ukraine, Russia has been seizing and delivering to Iran some of the US and NATO-supplied weaponry and equipment ditched by Ukrainian forces on the battlefield. The Pentagon suspects Tehran would try to reverse-engineer the systems.

According to CNN, over the last year, US, NATO, and other Western officials have reported cases of Russian forces seizing smaller, shoulder-fired weapon equipment such as Javelin anti-tank and Stinger anti-aircraft systems.

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Russia has, reportedly, flown the equipment to Iran to disassemble and evaluate it, most likely reverse engineer them.

According to the sources, Moscow is motivated to deliver seized Western weaponry to Iran because it will incentivize Tehran to bolster its support for Russia throughout the war. 

US authorities do not asses the problem to be widespread or systematic, according to officials. The Ukrainian military has been consistent from the beginning of the war in reporting any losses of US-supplied weapons to Russian forces. Yet, American officials admit that the situation is complicated and tough to follow.

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It is unclear whether Iran has successfully reverse-engineered any US weaponry obtained in Ukraine, but Tehran has demonstrated a strong ability to construct replicates of the US  of military equipment.

For example, the Toophan anti-tank guided missile, a strategic weapon in Iran's arsenal, was reverse-engineered from the US BGM-71 TOW missile back in the 1970s. 

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Additionally, in 2011, the Iranians intercepted a US-made drone, a Lockheed Martin RQ-170 "Sentinel," and reverse-engineered it to develop a new drone that penetrated Israeli territory in 2018.

“Iran has demonstrated the capability to reverse-engineer US weapons in the past,” said Jonathan Lord, a senior fellow, and director of the Middle East security program at the Center for a New American Security.

I spoke to @CNN’s @NatashaBertrand about the threat posed by Iran reverse-engineering US weapons. https://t.co/E3q3nz5uGf

— Jonathan Lord (@JonathanLordDC) March 10, 2023

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This coordination and delivery of seized weapons is evidence of Moscow's growing defense collaboration with Iran, which has developed in the previous year as Russia has become increasingly desperate for foreign military backing in its conflict with Ukraine. 

According to National Security Council spokesperson John Kirby, the collaboration is not only further destabilizing Ukraine, but it also "poses a threat" to Iran's Middle Eastern neighbors.