Friends, this is a major development; let me remind you President Reagan made a deal with Gorbachev; Gorbachev "tore down that wall" and because of that Reagan agreed not expand NATO eastward towards Russia. Subsequent American administrations have violated that agreement. The video below is excellent.
Russian Defense Report
The video report below brings together different recent media reports regarding recent Russian Technology announcements, and the recently deployed S-400 AD System in Syria.https://www.youtube.com/watch?v=goPmdbBZetQ