Trump, Syria, North Korea: Are we heading for a third world war?
Tensions in relations between the US, Russia, Syria and North Korea are rarely out of the headlines.
Donald Trump tweeted to tell Moscow to "get ready" for missiles to be fired at the regime of its Middle Eastern ally, Bashar al-Assad .
Senior figures from Russia warned that any missiles threatening its forces in Syria would be shot down and the launch sites would also be targeted.
But should it worry us?
Producer Tobias Chapple.