The word on many people’s minds in the business press for at least the past year has been “reshoring.”

Through some policy or another, presidents have promised to bring manufacturing jobs back to the U.S. since deindustrialization hit in the 1970s and 1980s, when free-trade agreements resulted in labor intensive industries moving their manufacturing bases to developing countries.

They make these promises because it sounds good. Americans like to feel that this is a country that makes stuff. Offshoring much of U.S. manufacturing, however, was not done in a day. It took place across decades.

Reshoring, whatever you think about how or whether it should be done, will take time. Bringing factories back to the U.S. will be a long, involved process. In the meantime, the latest effort to spur it is causing some disruption.

Tariff policy is becoming increasingly complicated — and talked about. President Trump, who likes to say “tariff” is “the most beautiful word in the English language,” is making imposing duties on goods from around the planet a key part of his economic revitalization plan.

At the time of this writing, there are 10% blanket tariffs on almost everything the U.S. imports, which includes raw materials manufacturers use to make their products or expand their operations. There are especially high tariffs on China, and that nation has retaliated with steep duties of its own.