Falling for the bait
The Israeli F-35s were destroyed in Iranian airspace on the second day of Israeli aggression on Iran, after the regime commanders believed they had severely damaged Iranian air defenses on the first day, Friday.
While the number and usual deployment of Iranian radar batteries can be estimated from open-source and intelligence data, distinguishing real air defenses from decoys remains challenging. These decoys are intended to mislead anti-radiation missiles, cruise missiles, and drones.
During the attacks, Israeli regime forces primarily used drones equipped with electro-optical (EO) and infrared (IR) sensors to strike radar installations. However, once these drones detonate, their sensors are destroyed, leaving operators uncertain whether they eliminated real radar systems or decoys.
Reconnaissance drones and satellites offer insufficient resolution for precise damage assessment. The only reliable verification would require agents on the ground deep inside Iran—a high-risk and unlikely scenario.
Iran has long been known to employ sophisticated military decoys, including radar batteries. These decoys are far more advanced than simple wooden mock-ups; some emit false radar signals to mimic real activity and can cost upwards of $10,000 each.
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Israeli drones targeted these apparent radar sites, believing they had crippled Iranian defenses and gained air superiority.
This miscalculation proved costly. On subsequent attacks, Israeli fighter jets ventured deeper into Iranian airspace, unaware that functional radar systems had been reactivated. Iranian air defenses surprised the Israeli Air Force by engaging and shooting down several advanced stealth fighters.
Had Iranian forces attempted to down jets on the first night without this element of surprise, their success would have been doubtful. Additionally, any wreckage from early shootdowns would likely have fallen into neighboring Iraq, offering Iran little opportunity for technological study. 
Decoying is one of the most under-appreciated aspects of warfare, when used at scale it can absolutely wreck even the most sophisticated intelligence gathering systems