It's no surprise that Dr. Nathan Elkins-- one of the AIA's chief proponents of import restrictions on common historical coins of the sort collected worldwide-- claims that any coin type that circulated "predominantly" in a given country should be placed on the "designated list" for restrictions when it's easy for him to generalize that coins circulate "predominantly" where they are made.
But the governing statute, the Convention on Cultural Property Implementation Act, calls for much more. Assuming other statutory criteria are also met, it only authorizes seizure and forfeiture of artifacts "first discovered within and...subject to export control by" a given country. 19 U.S.C. Section 2601(2)(c).
The ACCG has indicated that the Government could comply with the plain meaning of the CPIA in either one or two ways: (1) establishing by undisputed scholarly evidence that the coins placed on the designated lists could only have been discovered in a given country for which import restrictions are granted and, hence, must be subject to their export controls; or (2) demonstrating by documentary evidence that any coins Customs seizes were in fact discovered in that country and, hence must be subject to that country's export controls.
The ACCG and others have offered scholarly evidence to suggest that ancient coins as a general rule circulated far from where they were minted. The fact that some (local bronze coins) typically circulated closer to home than others (precious metal coins and Imperial bronze issues) does not excuse the State Department's and U.S. Customs' efforts to ban coin imports based on place of production rather than on find spot.
The overbroad import bans Elkins and the AIA support threaten to cut off collector access to the vast majority of ancient coins openly available on the international market. In contrast, restrictions squarely linked to find spots are more narrowly tailored to deterring pillage of archaeological sites. That, of course, is the primary goal of the CPIA; not the furthering of nationalistic impulses that lay claim to any unprovenanced coin as the presumptive state property of the AIA's allies in foreign cultural bureaucracies.