- 604ft Belgorod sub was deployed yesterday in wake of incident with British ship
- Boasting heavy nuclear firepower capable of leveling an entire city, the vessel is the largest submarine of its kind to be built in the last 30 years
- Naval experts claim team aboard Belgorod will report directly to President Putin
- Comes just days after HMS Defender was fired upon by Russians in Black Sea
- British destroyer has now docked in Georgian port after high-profile standoff

