Separately, but obviously in a coordinated effort, the US and the European Union last week filed complaints with the World Trade Organization (WTO) alleging that China is blocking the export of certain raw materials to give competitive advantage to its domestic manufacturers in a handful of sectors.

The raw materials in the dispute include bauxite, coke, magnesium, manganese, silicon metal and zinc. China is a top producer of these materials, and limiting their export could provide an advantage to Chinese metal and chemical manufacturers that use these raw materials as key inputs.

U.S. Trade Representative Ron Kirk called China's alleged export restraints on raw materials a "giant thumb on the scale" that gives advantages to Chinese companies in those industries.

The complaints to the WTO say China is limiting exports on those products through quotas, export duties, licensing and other restraints. It is in one sense an ironic departure from the usual charges that China is artificially keeping its currency value low or providing subsidies that flood world markets for Chinese-produced products. However, raw material export restraints could make it harder for Western companies to sell some products into China, and/or give China an advantage in exporting steel, aluminum, chemicals and other products into global markets.

The complaints will trigger official WTO processes, which will start with China “consulting” with the WTO on the complaints within 10 days. China has denied the charges, and also used an environmental play, saying that some of the restrictions were imposed to protect the environment.

On the EU side, EU Trade Commissioner Catherine Ashton noted the impact on manufacturing costs for Western companies, as "the Chinese restrictions on raw materials distort competition and increase global prices, making things even more difficult for our companies in this economic downturn."

The complaints add another interesting twist to the moves in recent years by China to secure access to raw materials by investing in or buying outright raw material sources across the globe, especially in Africa and South America.

The moves have started to raise some concerns among Western nations. That was a key factor earlier this month when Chinalco, a Chinese state-backed aluminum company, was forced to walk away from a $19.5 billion offer to purchase a large chunk of Anglo-Australian mining giant Rio Tinto, which controls a huge amount of global iron ore production, after strong resistance to the deal developed, especially in Australia.

That included a provocative quote from former Australian Treasury head John Stone: “Once in the spider’s parlor, the fly doesn’t often get out.”