The S-400 Triumf, previously known as the S-300 PMU-3, is a mobile surface-to-air missile (SAM) system developed in the 1990s by Russia's NPO Almaz as an upgrade to the S-300 family of missiles. The S-400 was approved for service on 28 April 2007 and the first battalion of the systems assumed combat duty on 6 August 2007. The system is complemented by its successor, the S-500.
In a devastating escalation of hostilities, a Russian S-400 missile struck a police building in Kharkiv, Ukraine, on Friday,..