Amateur radio invites users worldwide, but the rules and usage differ region to region, sometimes significantly.
On most Stack Exchange websites, regional tags are avoided in preference to generic questions and answers that are universal.
I don't think this is going to be the case here, though, and regional tags will be necessary if we are to allow questions with significant regional differences, such as band plans, licensing, etc.
Things which are generic don't need to be tagged, for instance radio design and development often will be universal.
I've create the USA tag, for instance, as the entire US is governed by one radio emissions standards body. I presume we're going to be tagging country by country, but are there other aspect of this we should discuss and prepare for as we start tagging questions regionally?