On the night of 25-26 July, Ukraine attacked one of the most advanced Russian air defense systems – a battery that was deployed in Crimea at the time. Ukraine’s military and the organized resistance on the peninsula that support them have been gradually “chipping away” at the air defense network in Crimea. At least 5 to 7 entire S-400 batteries or their core battle manager command positions have been either heavily degraded or destroyed in Crimea since the war began. The S-400 missiles are the evolutionary, next-generation replacement for the famous S-300 family of air defense systems. Due to its advanced performance and the high price tag, the S-400 is the most sophisticated long-range air defense system that Russia can deploy against Ukraine.