The United States of America can established a tariff on clocks in order to protect those companies that are manufacturing clocks in USA, that is, the home industries. The two possible effects of imparting tariffs on clocks include decrease in the number of clocks that are imported and a possible retaliation from the affected country.
Due to the tariff imposition, the number of clocks that will be imported into USA will decrease and those countries that are exporting clock to USA may also impose tariffs on the goods that USA is sending to their countries.