Does having an IP [screenplay] copyrighted in one country make it binding in another country? In other words, If I copyrighted a script in the US… does that copyright also hold legal status in Ireland?
Every country has its own copyright laws, and so things do vary from place to place, but fortunately, most of the developed world 165 countries, in fact, have signed on to an international treaty, the Berne Convention for the Protection of Literary and Artistic Works Now, This is not a new treaty. It was first developed in France, at the urging of Victor Hugo in 1886. The US signed on in 1989.
The Berne Convention requires its signatories to recognize the copyright of works of authors from other signatory countries (known as members of the Berne Union) in the same way as it recognizes the copyright of its own nationals. For example, French copyright law applies to anything published or performed in France, regardless of where it was originally created.
So, yes, Vince, your script originally created under US Copyright law does enjoy protection in Ireland and 163 other countries.