KIRILL KUDRYAVTSEV/AFP via Getty Images
- Ukraine appeared to take out a Russian S-400 system in Crimea with Western ATACMS missiles.
- The S-400 air-defense system is more advanced than the older ATACMS.
- Experts told BI that S-400s are Russia's best, but their performance in Ukraine has been mixed.
Ukraine's latest claimed strike on Crimea is likely another example of how its older, Western-supplied missiles can foil even Russia's most advanced air-defense systems.