China, in retaliation for new U.S. tariffs, revoked its latest goodwill gesture of exempting some Chinese importers from its own tariffs on U.S. soybeans, but at least one U.S. shipment will get through unscathed, according to U.S. government and industry officials.

National Economic Council Director Larry Kudlow said Monday he expects China to drop its retaliatory tariffs on U.S. ag commodities very soon in order to boost imports, as promised.

Prospects for U.S. farm exports can change suddenly and dramatically. Breaking into foreign markets takes decades of persistent hard work and hefty investments in building infrastructure, relationships and, ultimately, sales.