Germany and Russia have a special relationship which is mutually beneficial to both, but not necessarily for the EU or NATO. Germany is the 5th largest energy consuming country in the world. Nearly half of its natural gas, a third of its oil, and a fifth of its coal imports come from Russia (http://www.eia.doe.gov/emeu/cabs/Ger...ackground.html). This has led to the development of the Nord Stream project, which can potentially save 1 billion USD annually for Germany by avoiding the fees on transit through Eastern Europe. 40% of the consortium responsible project is owned by Germany companies, and former German Chancellor Gerhard Schröder is the leading member of the shareholder's committee.

I think energy is the primary issue, but there are other secondary trade relations; such as German economic technical expertise to assist Russian development. Germany is the heavy-hitter on the continent and key for Russia's strategy in prevening an EU concensus to form against its resurgency.