Inter-nationally, a word that implies dealings or connections between different nations or countries, can be replaced with various synonyms, depending on the context of the sentence. "Globally" is a common alternative, as it suggests worldwide reach and impact. "Internationally" could also be interchanged with "cross-border," which suggests more specifically dealings between countries divided by a physical boundary. "Transnationally" and "intercontinentally" are other viable synonyms with the same implication. Essentially, inter-nationally can be substituted with any word that implies communication or commerce beyond national borders, but the specific term should reflect the nature of the interaction.