It was last cancelled after the US attack on a Syrian airbase in April.
Russia has announced it has suspended an agreement to share the whereabouts of Russian aircraft over Syria.
The sky incident prevention interactions agreement otherwise known as the ‘flight safety memorandum’ was previously cancelled by Russia after the illegal US attack on a Syrian airbase on the 6th of April 2017.
It was quietly reinstated shortly thereafter.
Russia is clearly furious at America for shooting down a Syrian aircraft which has impeded the Syrian fight against ISIS and other terrorist groups.