Bitcoin is already an international currency since you can do most of the things you can do with currency all over the world, what we are lacking is a bigger user base so we could use it in our everyday lives.
Well, maybe you're right. bitcoin has become an international currency when everybody started looking on the internet bitcoin. however, there are still some countries that can not use bitcoin, or have not recognized it as a currency because the price is not stable. but, I believe, one day they will admit it.
it is an international currency. People all over the world use it. On the long term i think it will get mass adoption.
Let's hope for this to happen.