China's announcement that it will impose controls on exports of some gallium and germanium products from Aug 1 has sparked consternation.

The metals are key materials for high-speed computer chips and electric vehicles, as well as for the defense and renewable energy sectors.

About 40 percent of the world's germanium, a metal even rarer than gold, is in China, which accounts for over 67 percent of the global supply. The US possesses about 45 percent on its territories, but due to pollution concerns and strategic considerations, it produces little and exports even less. China has the largest resources of gallium, known as the "backbone of the electronics industry", and it produces about 95 percent of the global supply.

The control on exports of eight gallium and six germanium products mean the authorities will reject export applications if they are to be employed for military use or purposes that may undermine China's national security and interests.

While Chinese Foreign Ministry spokeswoman Mao Ning said such control on exports is a common international practice, and clarified that it does not target any specific country, the timing of the Ministry of Commerce's announcement is telling.

The announcement came just ahead of US Treasury Secretary Janet Yellen's visit to Beijing, which begins on Thursday, with the timing widely interpreted as sending a message to the Joe Biden administration, which has been attacking China's chip sector with export restrictions and putting pressure on other countries to follow suit, that Beijing has the means to fight back.

The move is Beijing's second response to the United States' continued weaponizing of export restrictions to target the country's high-tech sector, and its co-opting and coercing of other countries to join its offensive. In May, it introduced a ban on some key domestic industries from purchasing products and services from US memory chipmaker Micron.

Peter Arkell, chairman of the Global Mining Association of China, was reported as saying that Beijing's latest move "has hit the American trade restrictions where it hurts".

Gallium and germanium are just two of the metals that China is the dominant producer of and which are important for a range of tech products, and Arkell said "it is a fantasy to suggest that another country can replace China in the short or even medium term".

Those challenging China's decision should challenge the US, Japan and the Netherlands on their chip or equipment export controls targeting China.

It is they that should be blamed for necessitating such an action by Beijing, which is just defending the country's interests in the face of their concerted tech attack.