Craig, with respect, that's not really the way it works. The question of "which law applies" implies (a) that a person is attempting to enforce a right of copyright, and (b) some judicial or administrative body is applying the law. Copyright isn't a "thing" that attaches to somebody; it is a legal right that is asserted by the person claiming copyright.
I had assumed, from his profile page, that the OP was from the US and would seek to enforce an infringement of his copyright in the US.
Read article 5 of the Berne Convention again in its entirety. Tell me whether you can envision ANY scenario in which the court of a member state is applying foreign copyright law. Just to be clear, I'm not saying that courts never apply foreign laws, I'm just saying that article 5 has nothing to do with this. Under article 5, US law applies in the US, French law applies in France, Canadian law applies in Canada, and Japanese law applies in Japan. Article 5 gives a foreign person the right to enforce his or her copyright in a foreign land. But it doesn't mean that the courts in that foreign land won't be applying its own domestic laws.
I also think that you're misunderstanding how country of origin is determined. See especially paragraph 4 of article 5.
Finally, consider the consequences of your interpretation to an action brought by National Geographic to enforce its copyright in the US.
Berne Convention (full text)
http://www.wipo.int/treaties/en/ip/berne/trtdocs_wo001.html