Don't overestimate them. I don't believe MS or US government would give access to source code to anybody with "alternative" world insight. It's like to give access to source code to N. Korea.
Well, for Win 7 MS had a "special co-operation agreement" with the modern Russian analog of the KGB agency, and disclosed Win 7 OS source code in full. There also was co-operation around Win 8 http://www.gazeta.ru/business/2011/12/01/3854510.shtml, but not around Skype sources.
Not sure what your point is. Also, not sure why my factual comment has been downvoted. (Is this reddit?) However, there is no shortage of info for anyone who knows how to use Google. To quote Computer Weekly:
An agreement signed in 2002 gave Russia access to the source code for Windows XP, 2000 and Server 2000.
Under the latest agreement, Russia will gain access to the source code for Windows 7, Server 2008 R2, SQL Server and Office 2010.
All governmental requests (whether from local, state, provincial, or national governments or agencies) for access to Microsoft product source code must be directed to the Government Security Program Team. They can be contacted at gspteam@microsoft.com