It was a multinational effort (US, Israel, Germany), mostly lead by the NSA.

detuur · on May 14, 2020

This must be the first time I've ever seen Germany implicated in this. I consider it 100 times more likely that the UK was involved than Germany.

dsl · on May 14, 2020

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.

ciarannolan · on May 14, 2020

From my very vague recollection of this from Countdown to Zero Day, there were some Germans (at Siemens?) who had expertise in the industrial control units that Stuxnet was attacking.

Definitely don't take that as fact though :)