President-elect Joe Biden promised on the campaign trail to reverse the Trump administration’s policy of breaking ties with Cuba, and that has U.S. farm groups once again hoping their farmers will benefit with increased trade.

China is again promising that it has made structural changes to its tariff rate quota system to import corn, wheat and rice, but it’s still not clear if that’s the case as the new deadline approaches for the U.S. to tell the World Trade Organization if it agrees.

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.