Kosovo can be a reason, but I'm not sure. It would make sense given the dramatic explaination Fischer gave at the time for make German to participate for the first time in more than 50 years in a war, just when the greens got to gov for the first time into gov, which originally had a strong pacifistic base. Now 'humanitarian interventionism' is seen by some as kind of duty

I don't know for sure and can only speculate

• the tradition of Brandt's eastern policy
  
• the same reason - whatever that is - that makes Germans much more likely to answer 'Gorbatchov', when asked who has made the most important contribution, to end the cold war, while Poles are likely to answer 'The pope' or 'The USA', especially the question who has allowed the German unification. The united Germany became member of the NATO and was generally percieved as becoming a member of the west, so one could have expected more opposition by Russia than by western allies.
  
• Kohl's friendship with Yeltsin + Schroeder's frienship with Putin ("Lupenreiner Demokrat")
  
• the fact that Putin supported Schroeder along with Chirac in the opposition to war in Iraq
  
• the fact that Georgia wants military aid/NATO membership; and then the same reasons would apply as why the Germans refuse to support the war in Afghanistan, even when it isn't called 'war' in the media, but just operation - there is a lot of principled antimilitarism in Germany independent of reason. The word 'Krieg' makes people fear. As you for sure have noticed, nobody says 'Krieg gegen den Terror' to translate 'war on terror'.
  
• the perceived special relation with Russia, and the break of the promise of special realtions with the US (I mean similar to the UK special relations)

The fact that Merkel and Steinmeier have both rather high ratings allows as well for wider forms of antiamericanism as reason, e.g.

• many people have the impression that Germany is too close aligned with the USA. That we are often vassals.
  
• all kind of bad things are believed can be done by US America

Putin by the way plays very well on many of these issues in his interview.

• He mentions Srebrenica to remind about the duty of 'humanitarian interventionism', where Dutch troops have failed this duty.
  
• He implies Europeans don't follow their own interests, but the US interests.
  
• He suggests Saakashvili could have done the bidding of the US gov and helping McCain in the election.

Der Amerikaner ist die Orchidee unter den Menschen
Volker Pispers