A tariff is a duty imposed on goods when they are moved across a political boundary. They are usually associated with protectionism, the economic policy of restraining trade between nations.

关税是指国家授权海关对出入关境的货物和物品征收的一种税。

youdao

It was such protectionism that led to the Smoot-Hawley Tariff Act of 1929--30, the precipitator of the Great Depression.

FORBES: Magazine Article

Eric Harwit, a professor at the University of Hawaii, says they are contemplating South Korean- or Japanese-style protectionism: red tape and other non-tariff barriers.

ECONOMIST: Is there any point in manufacturing cars in China?

So, a U.S.-first approach to currencies, or other trade protectionism such as industry subsidies or (always) tariff barriers themselves, is abhorrent.

FORBES: Right Is Caught Between China and Obamanomics