The Elements of Power

David Abraham Yale University Press, 319 pages, $30

The power to generate an electric toothbrush comes from tiny magnets using three rare metals: neodymium, dysprosium and boron. Some of these metals are so coveted that in 2010 they were at the center of a dangerous rift between China and Japan. In all, an electric toothbrush is made of 35 metals that might travel through countries such as China, the Republic of Congo or Turkey en route to American children. They are rare, says David Abraham in "The Elements of Power: Gadgets, Guns and the Struggle for a Sustainable Future in the Rare Metal Age," a thought-provoking book that follows the trail of these elements, not because they are necessarily scarce or hard to extract, but because they are used in tiny yet essential quantities — like yeast in a pizza — in products from iPhones to fighter jets.

As with oil, those who can secure the resources have access to immense power. The problem, the book laments, is that China, Japan and South Korea are more keenly aware of the strategic importance of rare metals than Western countries, including the United States. "The Elements of Power" turns out to be a critic as well as an advocate of the rare-metals trade, for example the "long tailpipe" of pollution left behind. While the book could have used more central narratives, Abraham persuasively explains the danger of underestimating a business that, by one estimate, plays a critical role in systems worth about $4 trillion.