Is the country with the one-year copyrights a Berne Convention signatory? If so, then it is in violation of the treaty, which sets a minimum term for copyright

Is the country with the one-year copyrights a Berne Convention signatory? If so, then it is in violation of the treaty, which sets a minimum term for copyrights. The WIPO may adjudicate and other signatories may take action. If not, then what you have is a national sovereignty issue. Other countries can restrict trade with the one with different laws, but they can't directly stop it from refusing to be similar to them (without a military invasion!). This is currently the situation with things like online gambling. It's legal in some parts of the world, and in others the citizens accessing the sites may be prosecuted, but the sites themselves are usually beyond the reach of the disapproving countries - often the USA. I should note that it is totally possible to have two countries with CONTRADICTORY laws that cannot be simultaneously satisfied. How would you deal with that situation, if all must be respected?