We’ll look at: • How the Cold War’s S-75 “Desna” led to the invention of stealth. • The real reason the U.S. poured trillions into radar evasion. • Why Russia’s modern systems like the S-400 and Pantsir are failing spectacularly. • How Ukraine’s cheap drones and missiles are bypassing billion-dollar SAM networks. • What this means for NATO strategy, procurement, and deterrence in the drone age.