The incorporation of "fair use" images in Wikipedia ensures that the encyclopaedia as a whole cannot straightforwardly be used/redistributed outside of the US.
As I keep pointing out "fair use" images aren't the only problem. Wikipedia has many photographs of old artworks. The photographs themselves are explicitly protected by copyright law in Europe but not in the United States as the Bridgeman ruling showed.
So, many of the images tagged "pd-art" or with other pd-tags aren't actually in the public domain in Europe.
And then there are books published before 1923 in Europe. Those are in the public domain in the United States but often not in Europe. The artwork of [[Arthur Rackham]] is a good example. A British reuser would do well to be careful in using those, their pd-tags notwithstanding. Currently few people pay attention to this as is demonstrated by the fact that one of these images was recently promoted to a featured picture. The featured pictures are the images on Wikipedia that have received the greatest scrutiny, including scrutiny of their license.
And I hear there may be problems with public domain images from U.S. federal agencies outside of the United States.
All in all a version of Wikipedia stripped of all images that could be problematic outside the United States would be stripped of *many* good images. I don't really think that's a good course to take. We should, however, be careful to tag everything clearly.
Regards, Haukur