Rare earth elements are increasingly important to modern life. They're required for metal alloys, for microwave ovens, for specialist glass, lenses, batteries, cleaning compounds, magnets, lasers, computer memory, x-ray machinery, fluorescent lamps, and basically every other piece of contemporary technology.
They're scattered in the ground, hard to get at, and in limited quantities. There are obvious financial incentives for controlling them. This puts them at the center of some rather nasty conflicts.
On the demand side of the equation, not only has China managed to corner 97% of global production, but they're now stalling exports elsewhere – the US, Europe, and most particularly Japan have all seen shipments from China held up.
Of course, China isn't just hoarding all of these supplies; its ever-growing manufacturing sector is consuming them at increasing rates. And the control it has now allows it to put pressure on the manufacturing sectors of other countries.
On the upside, this has forced at least Japan and Germany to begin taking recycling far more seriously. Recycling hasn't previously been considered practical because it would push prices up – but those prices are rising anyway, and there's no longer any real choice.
There is a significant dark side to all this economic activity. These minerals all come from somewhere.
Many of China's own mines are in Inner Mongolia but it, Europe, and the US still rely on imports of cassiterite, wolframite, and coltan from the Democratic Republic of Congo. The DRC's mining industries – and China itself – have been linked to funding the kind of militia and armies who use mass-rape as a weapon (in one case, at least 150 women and children were raped over several nights), all in the name of controlling mineral resources. Margot Wallström writes:
More than 200,000 rapes have been reported since war began in the Democratic Republic of the Congo more than a decade ago. The eastern part of the country has been labelled the rape capital of the world. Control of Congo's natural resources and minerals has always been contested, and these vast riches have fuelled the country's conflicts. They have helped enrich militant groups, who have employed sexual violence as a tactic of war.
The US has recently proposed regulations around the trade and use of conflict minerals. However, whether or not such regulations prove sufficient (it does not seem likely), they will have very little impact on China's 97% of the pie, and it seems unlikely that China will be interested in similar measures of its own.