They did this with rare earth metals. The price rose 10x this year, and America put the mine in San Bernadino back into production pretty quickly. Wasn't the end of the world.
They did this with EVERYTHING. The costs of manufacturing are roughly 1/3rd labor, 1/3rd raw materials, and 1/3rd power. China subsidizes power and raw materials (through various means). If it weren't for that, Chinese stuff would be about 70% the cost of US stuff (assuming 10% the wages, equal productivity, and the same material and labor costs).
Subsidizing stationary inputs (like roads, power, and pollution sinks) or stuff that's expensive to move (steel, coal, trained workers) is a way to force a country to industrialize. Subsidizing easily exported inputs (like rare earths) is less effective, as it just ends up in your competitors' final products.
The mine in San Bernadino isn't back in production. You're talking about Molycorp, and their Mountain Pass mine. It's scheduled for the end of next year (http://www.molycorp.com/AboutUs/ProjectPhoenix.aspx). And I believe that's with extensive federal loans or loan guarantees.
That's somewhat true. Prices rose tremendously across all rare earth metals, and they fallen back notably for some light metals.[1][2] That said, they remain high for heavy rare earth elements (HREEs), where China still dominates production.[3] (Mountain Pass is predominately a light rare earth element-producing mine).
Bottom line: The rare earth story only partially supports your point. That said, the lead time for a new mine is 5+ years, and solar manufacturing lead times may be much lower (and thus barriers to entry also lower).
