This is a sort of meta-licensing issue.
My understanding has always been that images appearing on Commons are supposed to be free in both their country of origin and in the US [1], since WMF is hosted in the US.
The US approach to Berne and related international obligations is fairly simple to understand though in some cases it has some wacky implications. In general, the US says that a work is protected by copyright in the US if and only if a comparable work created by a US citizen and published in the US would be protected. Or in other words, all works published in treaty countries are treated as if they were the works of US citizens (with the exception that certain historical notice and registration provisions are waived). For the purposes of this discussion, I'm going to ignore some of the nuances regarding timing of treaty signatures and URAA reciprocity, which may modify the conclusions in particular cases but not the general gist.
The philosophy behind the US implementation of Berne is an easy point of view to express, but it has some difficult implications. In particular, since the US does not honor the rule of the shorter term [2], an image may be subject to US copyright protection for longer (in some cases much longer) than it is subject to copyright protection in its country of origin.
As enumerated in Commons:Licensing there are many countries were the copyright term on all or some works is shorter than the 70 years pma usually applied in the US, e.g. China, India, Italy, Japan, etc. This creates a question. Once an image's copyright expires in the country of origin should it be included in Commons even if it hasn't expired in the US yet? Working precedent on Commons often seems to say yes, though a strict reading of copyright law would seem to say no.
In addition, there are substantial classes of images, including parts of Freedom of Panorama [3] in particular, where copyright law in other countries includes exemptions that have no corresponding exemption in US law. It appears that Commons routinely includes such images, even without considering whether a comparable image produced in the US would be free or not. In at least some cases, this suggests that foreign authors could use US courts to enforce copyright protections in the US even when there would be no comparable protection available to them in their country of origin.
It seems to me that there are many images (and whole categories) where the only criteria for inclusion applied has been whether the image is free in the country of origin, without consideration to whether the work would also be free in the US. Or perhaps I am mistaken about this? Should we be reviewing all foreign images to decide whether a comparable US work would be free, and deleting ones that wouldn't be?
-Robert Rohde
[1] http://commons.wikimedia.org/wiki/Commons:Licensing [2] http://en.wikipedia.org/wiki/Wikipedia:PD#Rule_of_the_shorter_term [3] http://commons.wikimedia.org/wiki/Commons:Freedom_of_Panorama