For Donald Trump the decision to launch cruise missiles at a Syrian regime air base was a carpe diem moment. One that allowed him to seize on immediate opportunities.

First of all, it broke with Barack Obama's policy towards Damascus, re-establishing the "red line" his predecessor had allowed the Assad regime to cross.

For many, Mr Obama's failure to take military action after the chemical weapons attack in Damascus that killed hundreds of civilians in 2013 remains one of the biggest stains on his legacy.