Assad more or less handed Palmyra over to the "Islamic State" in May 2015, it was an intentional political move. His strategy was that the West would come help him fight the "IS." But it didn't happen because of course the West didn't want to help a dictator like Assad. That's why it was very important to him for Palmyra to fall into the hands of the "IS". Assad's troops defended the city against the "IS" for 48 hours and then just withdrew - after grabbing important documents from the archives and releasing the prisoners from the castle fortress. The situation now is similar: Assad did manage to get Russia and Hezbollah on his side to free Palmyra and celebrate himself. He's hoping to rehabilitate himself with the UN and be accepted again as a negotiation partner. It's a political maneuver.It was not really just "two days", the Palmyra offensive of May 13-26, 2015 was one of the largest offensives launched by ISIL, with the result of increasing the group's control of Syria to at least 50%. ISIL took key points outside the town on 14th May, the Syrian Army was reinforced 15th including by the special forces unit, "Suqur al-Sahara", and on 16th May pushed ISIL back. It was still advancing on 20th May when ISIL renewed its push after 600–800 militant reinforcements arrived. It was on 21st May 2015 that some artefacts were removed from the Palmyra museum by the Syrian curators and transported in two trucks to Damascus at the same time as ISIL began to take part of the town in street-to-street fighting. ISIL overran the whole town by the evening of 21st May. Reportedly the Syrian officers abandoned their posts, leaving conscripts to continue fighting and eventually be captured by ISIL together with the civilians. In early July 2015, the Syrian military launched an offensive in an attempt to retake Palmyra and attacks lasted until at least early August. It was only after this that ISIL began the publicised destruction of the Belshamin and Bel Temples which date to just after this, the tower tombs, a funerary temple and the Colonnade's Triumphal Arch were blown up later.
I really do not see that there is any evidence that Ms Sartre-Fauriat is correct in her Eurocentric interpretation of this part of the conflict, at what stage does she allege the decision was taken to "let" the city fall to ISIL? The truth is that the oasis-town was and is an important communication node and both sides wanted it. In May 2015 morale was low in the Syrian army, losses were being experienced on several fronts and forces were spread thinly. Yet this was a period when ISIL was advancing on several fronts. I do not see why Ms Satre-Fauriat thinks they could have been stopped here at this time.
She sees her organization as somehow central to everything, asked whether Palmyra can be rebuilt, she suggests:
Without help from abroad - that is, from UNESCO - it won't be possible.Ha! There being no potential sponsors anywhere in the world who'd be interested in doing some philanthropic financing resulting in replacing something as specacular as these monumensts? What about the simulacrum of a bit of the Temple of Bel they are erecting in London right now, did UNESCO finance that and for how much?