Russian Yakhont anti-ship cruise missile. Photo: Wikimedia Commons
The S-300 is entirely compromised it seems. Many times it’s just flat out been ECM’d. I think these next ones are probably not much better against ECM. The USSR/Russians never really did much combat against ECM, and they always got slammed in real combat. Often to the point where their systems were probably worse than having nothing at all.
P-800 Oniks Yakhont Anti-ship Cruise Missile Launch - Lateral Thrusters at Work
Smart strategic move, on the part of the Russians. The missiles might keep U.S. ships away; yet they aren’t a specific threat to the U.S., unless the U.S. becomes the aggressor, and makes the first move.
(Well, it should since it was a joint project...)