Retired Colonel Viktor Litovkin, a military analyst, said the US Air Force F-15 may have been brought down by an Iranian air defense system of Soviet or Russian origin. In his assessment, the most likely candidates were the Tor-M1 or the S-300 surface-to-air missile systems.

Litovkin noted that the tracked Tor-M1 can be redeployed quickly and, with a range of roughly 20 to 30 kilometers, would have been capable of reaching an F-15. He also pointed to Iran’s S-300 systems, saying he would not rule out that they are still operational.

He added that the Iranian military also has man-portable air defense systems such as the Igla and Verba. Although their range is more limited, he said they still pose a threat to aircraft. According to Litovkin, such systems can engage targets at distances of up to 10 kilometers, meaning even a single serviceman carrying one could have endangered the American fighter.

In his view, the United States showed excessive confidence in the conflict with Iran. Litovkin argued that Washington likely believed it had fully suppressed Iran’s air defenses, which led US aircraft to operate with little regard for remaining threats.

On April 3, a two-seat American F-15E was shot down over Iranian territory. Axios reported that both crew members made contact after ejecting. One of them was rescued several hours after the crash, and the US side later announced that the second crew member had also been recovered.