The Conversation suggests that "the international laws that protect antiquities and cultural treasures are actually fairly strong, at least on paper":
The problem doesn’t lie with inadequate laws, but rather with compliance and enforcement.Certainly compliance and enforcement are problematic, but that is not in spite of the law being strong on paper but because the apparent strength of the law is belied by the small print in which its enforcement mechanisms are established and its purview defined. Of course, no enforcement mechanism save an invasion force could expect to deter a group that deliberately commits war crimes for TV cameras for the sake of showing contempt for the law. The idea of parachuting the carabinieri into Syria to secure sites against ISIS' iconoclasm is ludicrous, as is the notion that looting and trafficking of antiquities can be brought under control if only we have the will to enforce the laws we have now. Having the will and having the way are not the same thing. The 1970 UNESCO Convention has had very little effect in stemming archaeological looting even in states that are functioning and trying to fight the black market, because the Convention is badly designed as law and because protecting sites and policing a powerful black market is enormously expensive.
Nonetheless, sites must be secured and the black market must be policed. To do that, three things are needed. First, better regulations (for instance, transparency requirements for antiquities sales) that make it easier to identify looting networks and for police to work together internationally. Second, changes in museum policies to take the steam out of the illicit antiquities market by setting up antiquities loan programs; instead of paying $100,000 for a looted artifact and incentivizing further looting, the same collector would pay, say, the British Museum $100,000 for the privilege of borrowing for a time an artifact from the storeroom. The revenue generated could be used in turn to help finance more and better policing (the potential of new technologies in this area is enormous). Much more revenue, however, could be generated by a third legal-regulatory change: a tax on high-end antiquities purchases. The key point here is that we need to think much more creatively not just about what we would do if only there were more money to do it, but about how to raise that money and how to make it less costly to do what needs to be done.