One of the many open fronts in Mexico with Donald Trump and which is less obvious – but is more likely to cause immediate damage- It’s water.

The conflict has a historical background: According to a treaty signed in 1944, Mexico should send 2.16 billion cubic meters of water to the US to five -year circles, or average 431 million cubic meters of water a year from its tributaries in Rio Grande. At the same time, it expects to receive 1.85 billion cubic meters of water per year from the US via the Colorado River.

The Pact, which was welcomed as a demonstration of transnational cooperation, provides a diplomatic mechanism for resolving disputes affecting local communities and has preserved hydrological resources at the Mexican-US border from its signature.

However, since the early 1990s, Mexico struggles to fulfill his obligations, annoying US farmers and other Texas businesses dependent on Rio Grande for irrigation. As droughts and water deficiency have worsened, so is the violations of the Mexican agreement and border tensions. During the current five years, the country has so far delivered just above one -third of the projected water. Is unlikely to cover the difference before the circle ends in October.

The deficit already has push Trump to start warnings: Earlier this month, threatened to impose duties on Mexico“Maybe penalties” if the government does not send water to Texas. In an unprecedented decision, the US rejected a Mexican request for special water delivery in Tijuana in March, citing the country’s failure to fulfill the treaty. Mexico’s president, Claudia Sinbaum, responded with sharpness, saying that her country would deliver more water to Texas, that the forthcoming rainy season would also help that both governments would end up in “a reasonable agreement”.

But Sinbaum only buys time: Mexico does not have enough water to comply with the treaty. In addition, the delivery of additional supplies to the US should be done to the detriment of Mexican farmers. Rosario Sanchez, a senior researcher for the Texas Institute of Water Resources, estimates that even the redirect of the entire water of Nuevo León and Tamaulipas of Mexico – an impossible choice – would not be enough to fulfill the country’s obligation to the US. “The problem has already escaped at the level that should not be enough,” he told me. “Only a great hurricane could fill the tanks this summer.”

Yet Conflict affects American farmers And the state of Texas, two Republican constituencies that Trump wants to keep happy.

Today’s environmental reality is very different than when the treaty was signed more than 80 years ago: climate change affects rainfall, droughts are more common, water consumption has multiplied as population and businesses are expanding. Meanwhile, water quality has been degraded and an aging infrastructure causes more waste.

Franck Gbaguidi, Eurasia Group’s viability manager, reports New investments in hydrological infrastructure and behavioral changes around the demand and pollution of water as possible long -term solutions – while warning that caustic rhetoric will intensify in the coming months. “Accusing Mexico for lack of water in the southern US is a politically convenient narrative for the Trump government.” “Sheinbaum’s hands are tied. It can also adopt a more populist attitude, probably accusing foreign companies, especially those based in the US, to deteriorate water scarcity. “

Once it is confirmed that Mexico cannot provide all the projected water for this year, the best road is both countries to negotiate a new framework within the Treaty. Lack of water affects both sides and governments need to find a technical solution to a problem where everyone is going to lose something. Mexico should guarantee the reliability and predictability of its traditions, as Texas requires, because businesses cannot plan without knowing when the water will reach. At the same time, the US should accept that Mexico must cut its missions, which has already happened with the distributions of the Colorado River.

A new framework with a more holistic approach to these structural problems would be the logical solution – but politics usually moves in mysterious ways. The danger for Mexico is that a fighting White House can push for complete renegotiation of the treaty, something that the Mexican government wants to avoid at all costs, fearing to add more uncertainty. Giving too much to the Americans in the water discussions would also be politically threatening for Sinbaum. Would a technical solution prevail after negotiations, as the Mexican president argues? Or are we in a conflict orbit for more drastic decisions?

The stakes are great: Unlike money, services or industrialized goods, water is something that everyone needs to survive.

*JP Spinetto is a columnist for Bloomberg Opinion that covers Latin American businesses, economic affairs and politics.