GROM is a fantastic organization. I've not studied them, only read about them in open sources, but the operational history that is publicly available is amazing.
GROM has worked with US forces since at least Haiti operations in 1994:
http://www.specialoperations.com/Foreign/Poland/Unit_Profile.htm
Dzenkuje bardzo, GROM
Just when I was thinking I better do a little studying about GROM - here comes a Freeper with a reference. What a terrific forum this is!
http://www.specialoperations.com/Foreign/Poland/Unit_Profile.htm