Deadly S-400 anti-aircraft missile 'ring of steel' protects Assad: US fears network of Russian air defense that can shoot down 80 planes at once from 248 miles away and is 'one of the most feared weapons in the world'
- US President Donald Trump has warned Russia to 'get ready' for strikes on Syria in an extraordinary tweet
- Trump told Moscow 'You shouldn't be partners with a Gas Killing Animal who kills his people and enjoys it'
- US has maintained the threat of missile strikes in the wake of Saturday's horrific chemical attack in Douma
- Russia ambassador to Lebanon says US missiles fired at Syria would be shot down and launch sites targeted
- The S-400 has been described as one of the most formidable air defence systems in the world
- It is capable of shooting down fighter jets and missiles and has a 248 mile range
- Russia has claimed the chemical attack in Douma was staged by White Helmets rescue volunteers