I want to create a RISK-style game in C++ with decent graphics, of course.
I would like to create a map with countries as buttons [I know that this is possible in java through extensions but I want to do this in c++]
Could anyone please help me find a suitable library?
You need to use a good graphics library that may have downloadable extensions to do what you want. Check out Qt. There are also some good gaming development platforms, but not being a game developer I can't personally recommend any. The good thing about Qt is that it is fully cross-platform and open source.