i think that bitcoin will become an internationally recognized currency in a few decades, after that most of the people will use it
Isn't it already an international currency? I mean you can buy a lot of stuff from around the world using btc.
but it will take some time for it to get into mainstream.If we see it that way then it was international right after it was made, because everything announced and use on internet is international as anyone from any corner of the world can use it, but as you said it would still take a lot of time to reach all the places in a physical form.