Tillerson is saying the US did not warn Russia
They did, but it was a "If you have any personnel in al-Shyrat, then you got 30 minutes to get them clear." Kind of phone call, according to reports by AFP and other news agencies. It's another reason why a large, active airbase like that one had so few casualties, and basically none of them civilians.
In comparison the UK was well aware that the attack was going to take place hours before hand in a personal call between the President and Prime Minister.
It's also made the French and Germans
volt face and urge the Russians to hold talks with the US to ensure there's no escalation.
Oh, and the Chinese Premier is there right by him at the moment, so it's a seriously clever international power play on his part.
That "Trump is playing 4D chess" thing seems to leap to mind as the airstrike sends out two messages.
1) The US has a leader at the helm again. (Hence so many leaders are celebrating).
2)
Do not fuck with it. U.S red lines regarding Syria were
pretty fucking clear and Assad's forces got too cocky and chose to cross one of them.