This has clearly not escaped the notice of the Chinese. China, which controls around 90% of the world's rare earth minerals - many of which are essential to advanced materials - has been blocking shipments of these materials to Japan for the last month. And now, according to the New York Times, it has "quietly halted some shipments of those materials to the United States and Europe".

At the same time, according to the journal Nature:

Alternative energy, biotechnology, advanced materials and fuel-efficient vehicles will be promoted in China's newly mapped 2011-15 development plan, according to a report published by the country's state council on 18 October.

In other words, China is simultaneously controlling the flow of materials that are essential to many new technologies, while actively working on the very technologies that exploit these materials.

Rare earth elements aren't that rare, despite the name. But in recent years, it has become increasingly unprofitable for economies outside China to mine and process them. As Technology Review noted a few days ago:

Rare earths are comprised of 17 elements, such as terbium, which is used to make green phosphors for flat-panel TVs, lasers, and high-efficiency fluorescent lamps. Neodymium is key to the permanent magnets used to make high-efficiency electric motors. Although well over 90 percent of the minerals are produced in China, they are found in many places around the world, and, in spite of their name, are actually abundant in the earth's crust (the name is a hold-over from a 19th-century convention). In recent years, low-cost Chinese production and environmental concerns have caused suppliers outside of China to shut down operations.

One solution to the looming monopoly is to begin extraction processes elsewhere. Another is to look for alternatives to these increasingly valuable resources. As Tim Harper of Cientifica wrote in a recent report:

Through the use of nanotechnologies we can now start to develop processes that do not use rare resources, for example using carbon nanotubes and metallic nanoparticles in polymers to make them conducting rather than applying thin layers of indium tin oxide.

There are difficulties to this approach, as Dexter Johnson at IEEE Spectrum noted. But one way or another, China's actions are shining a searing spotlight on some of the hidden dependencies of technology innovation, and some of the less obvious challenges to developing technology-based solutions to problems in what is becoming an increasingly resource-constrained world, no matter how you look at it.