Thank you, Beijing, for making it clear to Americans how short-sighted we have been for many years.

Chinese officials have issued a new threat as part of their reaction to President Donald Trump’s increases in tariffs on some goods imported here from China. His purpose is to force Beijing to lower trade barriers that harm U.S. companies and to curb abuses such as theft of intellectual property.

Some of the materials used in electronic devices such as cell phones and electric vehicles are rare minerals. Collectively, they sometimes are referred to as “rare earth.”

Instead of developing other, secure sources of such minerals, the United States has become dependent to some extent on China, which possesses large quantities of rare earth.

Now, the Chinese are hinting that in retaliation for Trump’s action, they may cut off our supplies of the minerals.

For decades, proponents of a global marketplace approach to economics have assured Americans that is in our best interests in both the short and long terms. So, we have allowed other countries to build up certain critical industries, including energy and steelmaking. In the process, the United States has become dependent on other nations for many products, including some critical to our national security.

Yes, that has meant lower prices for some goods, including steel and sometimes, gasoline. It also has resulted in other nations — or groups of them, as with the Organization of Petroleum Exporting Countries for many years — being able to influence both our economic and diplomatic policies by threatening to cut us off and sometimes doing so.

China’s threat on rare earth is one more reminder of how shortsighted our policies have been.