Why ISIS wants to erase Palmyra's history ?

Palmyra Temple
In "The Art of War," Sun Tzu notes that "the whole secret lies in confusing the enemy, so that he cannot fathom our real intent." ISIS is developing this logic in an obscene and seductive way, using the world's media to cultivate its barbaric image and recruit new members.
The austerely beautiful ruins of the Temple of Baalshamin at Palmyra in central Syria are the latest victims of staged cultural desecration, and bodies like UNESCO have reacted as ISIS hoped, by denouncing this as a war crime. ISIS gets publicity, attention, vilification. The world's media react and we supply ISIS their recruiting fuel and offer free advertising of more illicit antiquities soon to be on sale on the black market.The destruction and looting of heritage across Syria and Iraq is on an industrial scale. The Syrian Heritage Initiative of the American Schools of Oriental Research, among others, tries to document this pillage and loss.
Truth is scarce in all directions. The destruction of the Baalshamin was announced Monday; ISIS released photos Tuesday purporting to show explosives rigged up, an explosion, and rubble. But other reports indicate the destruction occurred a month ago. The images released shock but fail fully to document.
It is almost as if the horrific and pathetic  beheading last week of Khaled al-As'ad  the octogenarian antiquities expert in Palmyra who apparently refused to reveal to ISIS information about Palmyra's treasures -- failed to achieve sufficient attention (or income) and lacked the aesthetic impact value of demolishing a colonnaded temple.
    There is competition and gaming even in this tragedy. Announcements of these outrages, and subsequent statements of verification, come from the rump Syrian government of dictator Bashar al-Assad and form part of its efforts to appear acceptable -- as the opponents of ISIS and iconoclasm -- and part of the fight against terror.
    "My enemy's enemy is my friend" reaches literal and dangerous absurdity when the West finds itself almost de facto allies in this with Hezbollah and other unlikely bedfellows which comprise a Shia grouping against the Sunni extremists of ISIS.