When California needed a new Bay Bridge, they decide to buy it from China. China was the cheaper option, primarily because of lower cost steel produced in the sort of conditions that the Golden State’s NIMBYs, or “Not In My Back Yard,” prefer not to see. China’s blatant subsidies, lax labor standards, and eagerness to burn high-sulfur coal made for an irresistible deal. And so, thousands of American steel jobs were shipped to Shanghai. But the steel for the bridge was plagued with structural problems, and the overall project eventually ran billions of dollars over budget.

It’s boondoggles like the Bay Bridge that likely helped prompt President Trump’s recent decision to impose tariffs on steel and aluminum imports. There has been fiery criticism of the tariffs, to be sure. But it’s simply a necessary step to salvage a key U.S. industry. And there are important national security concerns that make the president’s decision doubly important.