Not sure about Poland but probably from there too. India I think is the big player now.Don't some U.S. firms utilize engineers from overseas in Poland..?
If a company wants to be global, having an office in the country being served (or nearby) is important. The bigger the business, the more important it is to have good ties and support. Having not just sales people but engineers local (to help solve problems), in the same time zone, is going to be critical at some point for continued growth.