Last week, the House of Representatives passed the Rare Earths and Critical Materials Revitalization Act of 2010, by a 324 to 98 margin. The legislation would support the discovery and development of rare earth sites inside of the U.S. in an effort to reduce the auto industry’s near-complete dependence on China for the minerals—which are an essential component in modern high-efficiency electric motors.

Rare earth deposits exist all over the world, including one major site in Mountain Pass, Calif. The trouble is, the minerals have been so cheap for so long that only China has found it profitable to mine and process them. But with that country now tightening its control of the resource as it spends tens-of-billions to grow a hybrid and electric vehicles industry virtually overnight, the days of cheap and abundant REE’s seem to be coming to an end.

Last month, China temporarily halted rare earth element shipments to Japan in retaliation for that country’s detention of a Chinese fishing boat captain. That ban lasted only a week, but in threatening to cut off REE exports—and then reportedly punitively complicating the customs process—China sent a clear message to Japan about its car industry’s reliance on the minerals and China’s grasp on their supply.

But thanks to promise of government investment credits and the perceived future volatility of the rare earth elements market, a few companies are finally taking steps to cultivate REE resources outside of China. In the United States, Molycorp is in the midst of a significant modernization and expansion project for a mine in Mountain Pass, Calif. That facility isn’t scheduled to be operational until 2012, but in Australia, Lynas Corp is expecting to begin production of rare earths by early next year.

All of this added production could prove to be unnecessary though, if a government-backed team of engineers manage to succeed in the development of electric motors that don’t rely on rare earth magnets to operate. The New Energy and Industrial Technology Development Organization of Japan, and Hokkaido University have teamed up to create one such motor that it says has the same power output as existing REE-dependent designs. Though still in the early stages of development, the motor could provide companies like Toyota and Honda with the means to completely cut Chinese resources headaches out of the equation.

So even though green car alarmists have long listed a potential rare earths shortage among the chief reasons why a growing hybrid and electric vehicle markets may prove to be unsustainable, it’s looking more and more like the long-term future of electrified transportation will not be threatened by a shortage of the resource.