Archonsod 说:
Not how it works.
A copyright claim is valid only in the jurisdiction it was filed in. If I file for copyright in the UK, there's nothing stopping someone in the US copying my work, it simply means I can prosecute if they attempt to make use of the work in the UK. There are no international treaties or laws covering copyright as such*, nor is one jurisdiction obligated to uphold the copyright of another; in fact there are differences in what individual countries allow to be copyrighted in the first place. In the US you can file copyright on software and business processes; the UK explicitly rejects such copyrights.
Infringement can only occur if you hold the copyright for a given work within the territory. George Lucas cannot sue me for distributing Star Wars in Iran, because he doesn't hold copyright of the work in Iran. In fact, I could freely file for copyright of Star Wars myself (assuming the Iranian patent office doesn't have restrictions regarding the amount of content I must have contributed to the work).
If Infringement does occur then your legal recourse is determined by the jurisdiction the offence occurred in. If I was to infringe your copyright in France then it would be French copyright law which would apply. One of the reasons people use publishers rather than simply having a print shop run off a few thousand copies of their book themselves is that publishers tend to have the resources to file for copyright in all applicable territories
* The EU is somewhat weird in this regard. There is a resolution to unify copyright and patent standards across the Union so in theory all one need do is register with the EU copyright office rather than each individual member. There's even an EU copyright office. However, as current EU law stands it's up to individual members whether they recognise an EU copyright or not. In typical EU fashion what began as an initiative to reduce beaurocracy has instead added another layer since people now feel they should register an EU copyright on top of those they would normally file just so they can be ready for the time the EU office takes precedence, which has been going to happen "any day now" since around 1996.
You Brits have always been weird with all your fancy common-law and such so I don't know how exactly it works over there, but I think you are wrong about the nonexistence of international treaties. Bern Convention if nothing else.
Also you are confusing (at least in the terms of the continental law) copright on one side and trademarks/patents on the other. While trademark or patent indeed needs to be registered, copyright is protected by the law from the moment the work is published and no registration is needed. That's how it works here on the solid land.
Edit: I did a little research on the British copyright law and yes, it is only Wikipedia, but still there is a remarkable level of reliability. Here it is:
Works eligible for protection: literary, dramatic, artistic or musical works, the typographical arrangement of a published edition, a sound recording, a film or a broadcast.
Qualification for protection: British law states that an individual's work
is placed under copyright law as soon as it leaves that person's mind and is placed in some physical form. The work qualifies for protection, if made after 1 June 1957, if its author is:
1. A British citizen, British dependent territories citizen, a British National (Overseas), a British subject or a British protected person or
2. An individual resident or domiciled in the United Kingdom
or another country to which the qualification clause extends or
3. A body incorporated under the law of a part of the United Kingdom
or another country which the qualification clause extends.
The work qualifies for protection if its first publication took place:
1. In the United Kingdom or
2.
In another country which the qualification clause extends.
Lists of countries which trigger qualification by the various clauses are made by Statutory Instrument (SI) periodically as needed
by changes in the accession status of countries to treaties like the Berne Convention.
Countries which signed the Berne Convention:
http://en.wikipedia.org/wiki/Image:Berne_Convention.png
So regarding the fact that the Berne Convention obligies its signatrories to enact similar standarts, you can expect basically the same legislation nearly all over the world. (But yes, you can probably distribute Star Wars in Iran, this particular long shot worked. (unless there is de facto the same legislation) )
Edited many times, because of the friggin' picture