The major dispute relates to the date. Should the museums disgorge artifacts that can't be traced back to 1970 as David Gill maintains or is a 1983 date more "reasonable" as "Culture Grrl" suggests? See: http://lootingmatters.blogspot.com/2008/06/towards-ceasefire-in-antiquities-wars.html and http://www.artsjournal.com/culturegrrl/2008/06/towards_a_ceasefire_in_the_ant.html
Before jumping on the band waggon, I hope others will consider the difference between voluntary guidelines for current acquisitions and the repatriation of artifacts already in AAMD member collections. Repatriation decisions should never be taken lightly, particularly when lack of provenance information does not necessarily mean lack of good faith.
Significantly, both the 1970 and 1983 dates Gill and "Culture Grrl" propose are mere constructs. The UNESCO Convention may have been promulgated in 1970, but the US only adopted it with reservations. Those reservations-- embodied in the 1983 Convention on Cultural Property Implementation Act (CPIA)-- were meant to ensure that the US retained its "independent judgment" in such matters.
Put another way, the UNESCO Convention is not self-executing. Rather, for it to be given the force of US law, another signatory must make a formal request to the State Department for import restrictions on cultural artifacts. The Cultural Property Advisory Committee (CPAC) is then responsible for reviewing that request. It makes recommendations to the State Department decision maker (currently Goli Ameri) about whether and to what extent import restrictions should be imposed.
A number of source countries known for their aggressive repatriation efforts-- including Egypt, Greece and Turkey-- have never made such requests for import restrictions under the CPIA. To date, there are only import restrictions imposed on artifacts from 12 UNESCO Convention signatories. (Iraq is a special case. A Congressional statute provided the State Department with special authority to impose "emergency import restrictions" without CPAC review.) Most of the beneficiaries are poor nations which arguably do not have the resources to protect artifacts from looters. The exceptions are Cyprus and Italy, two wealthy EU members. A request from China made in 2005 remains pending.
These restrictions have been put in place at different times. For example, restrictions on ancient artifacts from Italy (excluding coins) were first imposed in 2001. Restrictions on Cypriot ethnological artifacts were imposed in 1999. Those on archaeological artifacts were first imposed in 2002. In 2007, these were controversially amended to include coins. For more, see: http://exchanges.state.gov/culprop/chart.html Under the circumstances, if an "operative date" is to be chosen, shouldn't it be the date import restrictions were imposed on artifacts from a specific country and not a more general 1970 or 1983 date based on a Convention that is not even self- executing?
In any event, the effect of restrictions is not to require the return of artifacts already on display. Rather, it is to preclude on a going-forward basis imports of undocumented artifacts "first found in the ground" in countries for which import restrictions have been imposed. Accordingly, those advocating that AAMD members should disgorge artifacts based on an artificial 1970 or 1983 date are basing their claims on little more than an artificial construct. But in making judgements on whether to denude our museums of artifacts long on display, AAMD members have a much higher obligation. They should continue to hold, study and display such objects for the benefit of the American public unless and until a claimant demonstrates some legal obligation that supports repatriation.