So apparently Kuwaitian F-18 shot down the 3 F-15s. What I don't get: did the IFF not work?
If the US is allied to a country and supplies the country's equipment there should be up to date transponder codes or however it works. Did it fail entirely on board of the F-18?
https://en.defence-ua.com/analysis/new_details_on_historys_most_expensive_friendly_fire_one_fa_18_hornet_defeats_three_us_f_15e_strike_eagles_setting_new_record-17709.html