There are many reasons for the current escalation of tensions in Syria.
First, Putin's leadership is under pressure after the poisonings in Salisbury.
Second, Trump's leadership is under pressure as investigations into his past actions get closer to the surface.
Third,Theresa May's leadership is under pressure because of Brexit.
The fear of war redirects the attention of the world media and consequently the world population. While this sabre rattling continues everyone will forget about elections, scandals and mundane politics.
Their might be a few casualties a missile here and an aircraft there but after a month or two they will all go back to allowing people to kill one another with the bombs that they all manufacture and sell to arms dealers. Chemical warfare is not that different to conventional warfare - it kills lots of people.
To stop a war, stop the supply of money, weapons and all other logistics. They can't buy guns without money. Guns can't shoot without ammunition, soldiers can't march without food.
This escalation suits all the parties involved at this time but beware the law of 'unexpected consequences'.