cross-national and cross-cultural academic collaboration
I don't know if there is such a platform.  It would be a good idea, but a lot of work to create one.

If one does not exist, I suggest you 


make a website where you post about your own work, and comments about others' work.  My partner is a physicist and made a primitive website. Believe it or not, strangers find this website and make contact to initiate collaborations.
look on Google Scholar for articles that interest you.  Write to the authors of the articles that really intrigue you.  I have done that.  Rarely, there's no answer.  Sometimes, there's a one-line email and an attached article that is exactly what I was hoping to find.  Sometimes, there is an invitation to collaborate on a specific project!