For all but clusters of ideologically twisted jihad-groupies worldwide, the burning alive of Lieutenant Muath al-Kasaesbeh, the Jordanian pilot captured in December, proves the Islamic State of Iraq and the Levant has depths of depravity that are fathomless. But what matters most now is how local, Sunni and tribal reaction towards this self-appointed Islamist Inquisition evolves. Could this be the beginning of Isis over-reach, on the path to self-destruction?

Jordan’s reaction to the exultantly videoed immolation of Kasaesbeh was to execute two jihadis convicted in the 2005 suicide bombings by al-Qaeda of hotels in Amman. They were part of the network of the late Abu Musab al-Zarqawi, the Jordanian-born al-Qaeda leader in Iraq who helped spawn Isis and who was adjudged the most bloodthirsty jihadi cut-throat the region had seen.

Zarqawi’s organisation was the precursor to Isis, now led by his former, even more savage henchman, Abu Bakr al-Baghdadi, the self-proclaimed caliph of the Islamic State he declared in the swaths of eastern Syria and north and western Iraq seized by his jihadi army. His and their motives in this hideous murder bear examination.