The terror group's prophetic message leaves it vulnerable to a crushing defeat.
A 1400-year-old Islamic prophecy made by the prophet Muhammad has created a unique opportunity for Australia to strike a strategic blow against Islamic State.
In anticipation of Australia's decision to expand its military commitment into Syria, together with the recently revealed discussions between the United States and Turkey to clear IS from an area along Syria's northern border between the Euphrates River and the town of Azaz, offers the potential for a telling blow against IS. 
This is only because the last remaining area along the Turkish border controlled by IS includes a small and otherwise indistinct village known as Dabiq.
Islamic scriptures record Muhammad prophesying, "The Last Hour would not come until the Romans would land at A'maq or in Dabiq. An army consisting of the best of the people of the earth at that time will come from Medina. When they will arrange themselves in ranks, the Romans would say: 'Do not stand between us and those [Muslims] who took prisoners from among us.' ... They will then fight."
In Australia, Dabiq is known as the name of the magazine produced by IS that documents its gruesome acts, along with serving as a mouthpiece for its propaganda. In its first edition the magazine explained its use of the name Dabiq: "[I]t is taken from the area named Dabiq in the northern countryside of Halab (Aleppo) in Sham ... According to the hadith [sayings of Muhammad], the area will play a historical role in the battles leading up to the conquests of Constantinople, then Rome."
Since then, at least one IS hostage, or to use the terminology of the prophecy, "prisoner", was taken from where he was being held to Dabiq to be murdered. The video showing the beheading of Peter Kassig has "Jihadi John" telling the camera, "Here we are burying the first American crusader in Dabiq. Eagerly waiting for the remainder of your armies to arrive."
Bringing Kassig, a former US Army ranger, to Dabiq was a deliberately planned move to create a perception of the prophecy being fulfilled.
IS is deeply shaped by a particular understanding of Islamic theology that is focused on an "end of times" view of the world, in which human actions can hasten the start of the afterlife. This has led to the story of Dabiq becoming front and centre to much of IS propaganda.
Any deployment of foreign forces to secure the safe zone will be presented by IS as Allah's will being enacted through the fulfilment of the prophecy - unless, of course its fighters are defeated.
If this occurs, it will be hard for the organisation's recruiters, financiers and leaders to draw upon the idea that the IS fighters are the "best" among the Muslims as the prophecy requires. The finely tuned IS narrative of being the fulfilment of Allah's will on earth will be severely weakened and require the creation of alternative narratives to fill the group's propaganda.
That is why this effort cannot be half-hearted and why now is the time for Australia to join the US and Turkey in its efforts to clear IS from Turkey's border with Syria.
Were this effort to fail, by sending half-trained and ill-equipped proxies or by limiting it to a smaller area excluding Dabiq, or taking the area but not holding it, then it would be a lost opportunity playing into the hands of IS by reinforcing its image in the eyes of many Muslims and giving the group a warped moral impetus to pursue the prophecy further by pushing north to Istanbul: "[A] third of the army would run away, whom Allah will never forgive. A third which would be constituted of excellent martyrs in Allah's eye, would be killed, and the third who would never be put to trial would win and they would be conquerors of Constantinople."
If Turkey and the US mobilise to establish the safe zone, it is critical that Australia contributes forces and plays its part to take and hold Dabiq. If the international community fails to commit, if its members fail to take Dabiq, if they fail to clear every last fighter from the area, this will play into IS propaganda, giving it the largest boost to recruitment and propaganda win since the announcement of the caliphate in   June 2014.