Even if President Donald J. Trump was indulging in negotiating talk when he said he is “not looking to renew” the United States-Mexico-Canada Agreement, the remark gave US agriculture a case of nerves. And now he has officially decided against renewal, putting the free-trade agreement on a path to expire in 10 years. The USMCA, which replaced the North American Free Trade Agreement in 2020 during Trump’s first term, will now be subject to annual reviews for those 10 years.