TURKEY’S bombing of Kurdish YPG militia targets in Syria poses a similar conundrum to Arthur Conan Doyle’s “dog that didn’t bark in the night.”

The non-barking canine on Wednesday night was Russia’s S-400 and S-300 integrated air defence system that covers most of Syria plus much of Turkey, Jordan and Israel.

Moscow’s decision to install these state-of-the-art missile systems followed Turkey’s downing of a Sukhoi Su-24M bomber on the Syrian-Turkish border last November.