The government of Mexico earlier this month re-launched an old marketing campaign: Hecho en Mexico. A strategy that started back in the 70s, with the idea of promoting products made in our country. This is a worthy effort because we need to improve our internal markets.

Yet everybody knows the real motive: The slogan is a nationalist response to President Trump, who continues to threaten to re-negotiate NAFTA.

If our two nations re-negotiate NAFTA, as President Trump has sworn to do, Hecho en Mexico may become less an option than a necessity for Mexican consumers. Right now, U.S. goods and services are widely available south of the border. In 2015, for example, Mexicans bought nearly $18 billion in farm products from Americans. Not even the combined members of the European Union bought this much, and only the Canadians and Chinese bought more. Mexican dairy imports alone support 30,000 American jobs.

NAFTA allows Mexican consumers to enjoy choices like never before, letting us compare prices and quality between competing items. We discovered that we love American productsand their entry into our markets encouraged many Mexican companies to improve. Weve gone from building TVs that barely work to becoming the worlds top exporter of flat-screen televisions.

NAFTA makes me a better farmer, too. On our family farm in central Mexico, we raise more than 400 dairy cows, also growing corn and grass for feed on 40 hectares. Yet we purchase plenty of feed as well, and free trade with the United States and Canada makes it possible to buy high-quality yellow corn rather than depending on cheap sorghum.

Gina Gutierrez on her dairy farm in Pachuca, Mexico

Mexican farmers, in turn, have gained new opportunities to sell avocados, limes, and tomatoes. NAFTA even ensures that Americans have access to genuine Mexican tequila made from the blue agave plant.

Altering NAFTA puts everything at riskbut a re-negotiation also presents the chance to make a good agreement better. A revised deal, for example, could incorporate more e-commerce, which did not exist when our countries completed the pact in the early 1990s.

Agriculture has seen its own advancements, especially in seed technology. A new-and-improved NAFTA might persuade Mexico at last to permit GMOs, which so far my country has resisted despite their impressive global track record. Farmers like me want to take advantage of drought-resistant corn, helping us grow more food on less land and keeping consumer prices in check.

Yet its also possible to imagine a worse NAFTA. I worry that a botched agreement would force me to downsize my farmand additionally hurt millions of people on both sides of the border.

A re-negotiation that restricts the flow of goods, services, and technologies, would compel Mexico to search for new trade partners. We already have free-trade agreements with dozens of nations and were currently in talks to expand our ties to the EU. Were also likely to push ahead with a Trans-Pacific Partnership that improves our links to Australia, Japan, and New Zealand, even though it no longer includes the United States.

Think of it this way: If we cant buy grains from Americans, well possibly need to buy corn from Brazil and soy from Argentina.

I dont know why President Trump would want this, let alone the corn and soybean farmers from Indiana, Iowa, Missouri, and elsewhere who voted for him in such large numbers last year.

A U.S.-Mexico trade war helps nobody. We all suffered through a skirmish in 2009, when then President Obamas administration blocked Mexican trucks from American highways. My government retaliated with special duties on fruits and vegetables, slashing the incomes of the American farmers who grew them. Eventually we settled the disputebut in the meantime, everybody paid a price.

President Trump talks about putting America First. Fair enough: Leaders everywhere look after their national interests. Yet if this motto is just another way of saying Mexico Last, President Trump may become sorry about pushing our partnership into animosity. Throttling the Mexican economy is the surest way to encourage illegal immigration across the Rio Grande.

Lets keep NAFTA alive, with Made in the USA continuing to appear in Mexican markets and Hecho en Mexico showing up in American stores.

Were very different, but it is in that diversity that we must find unity. Were neighbors. We might as well be friends.