19 U.S.C. 1338, Discrimination by foreign countries

… <p class="statutory-body">Whenever the President shall find as a fact that any foreign country places any burden or disadvantage upon the commerce of the United States by any of the unequal impositions or discriminations aforesaid, he shall, when he finds that the public interest will be served thereby, by proclamation specify and declare such new or additional rate or rates of duty as he shall determine will offset such burden or disadvantage, not to exceed 50 per centum ad valorem or its equivalent, on any products of, or on articles imported in a vessel of, such foreign country; and thirty days after the date of such proclamation there shall be levied, collected, and paid upon the articles enumerated in such proclamation when imported into the United States from such foreign country such new or additional rate or rates of duty; or, in case of articles declared subject to exclusion from importation into the United States under the provisions of subdivision (b) of this section, such articles shall be excluded from importation.</p> <a name="substructure-location_e"></a> <h4 class="subsection-head">(e) Duties to offset benefits to third country</h4> …