You were quicker on the draw than I was Andrew...
The country most upset with Australia deciding to acquire nuclear submarines, rather than the previously planned French diesel subs, is China.
https://apnews.com/article/technology-joe-biden-australia-chinaChina said the alliance would severely damage regional peace and stability, and jeopardize efforts to halt nuclear weapon proliferation. It said it was “highly irresponsible” for the U.S. and Britain to export the nuclear technology, and that Australia was to blame for a breakdown in bilateral relations.
“The most urgent task is for Australia to correctly recognize the reasons for the setbacks in the relations between the two countries, and think carefully whether to treat China as a partner or a threat,” said Zhao Lijian, a spokesperson of China’s Ministry of Foreign Affairs.
Beijing has been unhappy with the Biden administration calling it out over human rights abuses in the Xianjing region, the crackdown on democracy activists in Hong Kong, and cybersecurity breaches. Biden spoke by phone with China’s President Xi Jinping last week. After the call, the official Xinhua News Agency reported that Xi expressed concerns that U.S. government policy toward China has caused “serious difficulties” in relations.