Treaties Do So.
Most foundries have very similar fonts derived from work largely designed by others. Other countries' copyright laws do not and never did supercede US laws regarding US acts and sales. Because of the strongly held, idiosyncratic beliefs of most nations, there was a core set of articles that most countries would subscribe to and there were large numbers of articles that some countries felt were important, where others were adamantly opposed. An appropriate analogy might be that of a cafeteria, where each country's legislative body picked their own choice of vegetables to go with the basic meal. These were articles that they refused to sign on to as part of the treaty.