I personally believe the German government was aware, but did not directly participate in a meaningful way. However a German corporation played a huge role.
Siemens engineers deployed a PCS 7 lab environment at the Idaho National Laboratory, where research in to exploits was conducted. Coincidently one of the methods Stuxnet used to stay hidden was demonstrated at the KEMA Control Systems Conference in Idaho Falls.
Separately, Siemens engineers built a replica of the Iranian system at Shimon Peres Negev Nuclear Research Center in Israel using P-1 centrifuges the US obtained from Libya's nuclear program.
Siemens engineers deployed a PCS 7 lab environment at the Idaho National Laboratory, where research in to exploits was conducted. Coincidently one of the methods Stuxnet used to stay hidden was demonstrated at the KEMA Control Systems Conference in Idaho Falls.
Separately, Siemens engineers built a replica of the Iranian system at Shimon Peres Negev Nuclear Research Center in Israel using P-1 centrifuges the US obtained from Libya's nuclear program.