Claudia Sheinbaum’s response to Trump’s threat of tariffs revealed truths that the president-elect doesn’t want Americans to know.

Donald Trump’s angry threat to impose 25 percent tariffs on all U.S. imports from Mexico—delivered Monday via the cautious diplomatic language of a Truth Social rant—is widely being depicted as a bluff. Trump declared that once in the White House, he will impose the tariffs unless Mexico stops migrants and fentanyl from “pouring” into the United States. Seen as a feint, the tactic could theoretically get Mexico to halt the migrant flow, allowing Trump to pull back on tariffs later while boasting that on the border, he has already bent Mexico to his will.

But amid all this parsing of Trump’s intentions, a crucial fact about his new move is getting lost: At the center of it is a lie. This lie is hiding in plain sight: It’s the underlying suggestion that Mexico is not doing anything to stop migrants from coming and that Trump’s threat of tariffs is needed to change that. Here we’re getting an early glimpse of how he will deceive voters about some of his most potentially destructive designs, on tariffs and immigration alike.

All this is laid bare by the sharp response to Trump’s threat that new Mexican President Claudia Sheinbaum issued Tuesday. Her statement is getting attention for its barbed claim that American guns trafficked to Mexico are fueling crime and violence there among gangs supplying U.S. markets with drugs. “Tragically, it is in our country that lives are lost to the violence resulting from meeting the drug demand in yours,” Sheinbaum noted acidly, suggesting that the two countries’ interrelated national challenges underscore the need for cross-border cooperation rather than Trumpian confrontation.

That’s a harsh indictment of Trump’s whole worldview. But this dry bureaucratic bit also deserves note:

You may not be aware that Mexico has developed a comprehensive policy to assist migrants from different parts of the world who cross our territory en route to the southern border of the United States. As a result, and according to data from your country’s Customs and Border Protection (CBP), encounters at the Mexico-United States border have decreased by 75% between December 2023 and November 2024.

What this polite (and euphemistic) language says is that Mexico is already acting extensively to thwart migrants who travel through that country—originating south of Mexico—so they don’t reach our own southern border. As Sheinbaum notes, this is partly why border apprehensions in the United States have dropped sharply of late.

It’s darkly amusing that Sheinbaum would cite U.S. statistics to make this point, because Trump does not allow that the reality depicted by our own data even exists. During the fall campaign, Trump endlessly repeated the lie that our “open” border is getting obliterated by a world-historical invasion, even as apprehensions plummeted and matched levels sometimes seen during Trump’s presidency. The latest numbers show that in November, apprehensions hit a new low under Biden and sank lower than some months under Trump.

Those numbers are relatively low partly thanks to Mexico. Adam Isacson, who tracks migration for the human rights group Washington Office on Latin America, put together a chart using Mexican government data that illustrates the point. It shows that Mexican forces have been apprehending tens of thousands of migrants traveling to the U.S. through Mexico each month (and sometimes over 100,000) up through August, the last month of available data:

As Isacson shows, another big thing keeping illegal border crossings down is Biden’s CBP One app, which allows migrants to make appointments to enter temporarily via various programs in an orderly, lawful manner. (Trump will also end that program, nixing something that’s contributing to reductions in crossings, because his paramount goal isn’t border security, it’s fewer immigrants here.)

The reporting bears out the bigger dynamic. As The Washington Post and The Wall Street Journal document, the Mexican government is using elaborate security operations to shuttle migrants heading for the U.S. border back south through Mexico. According to The Post, Mexican officials call this “El Carrousel,” or “the merry-go-round.”

Some experts see Biden’s private diplomacy with Mexico’s previous president as a critical ingredient in making all that happen. This cooperation, plus Biden’s recently imposed restrictions on asylum seeking and the CBP One app program, are all major contributors to this year’s lower apprehension numbers, Isacson says.

“If Trump wants Mexico to crack down on unauthorized migration through its territory,” Isacson told me, “then Biden has already gotten Mexico to do that to a greater extent than anyone has ever done before. He did it without tariffs.”

During the campaign, Trump simply pretended none of that was happening. It’s one of MAGA’s biggest deceptions, and his latest scam carries it forward. The very idea that Mexico must be bullied with tariffs into cracking down on migrants is designed to imply that it’s doing nothing right now—it’s taking advantage of us, Trump might say—and only his fearsome threats can force it into submission.

This massive swindle is getting lost in the coverage. Much of it is focused on the potential consequences of tariffs, such as upending trade throughout the Americas and creating extensive hardship for U.S. industries. That’s understandable, since the damage could be severe, but you can read whole articles about this that don’t inform you that Mexico is already doing much of what Trump wants it to do—or that this was apparently accomplished through diplomacy, without Trumpian bluster.

All this paves the way for larger deceptions later. Bank on it: The moment Trump takes office, the lower apprehension numbers will magically become real metrics. Fox News will start trumpeting them, and Trump will start claiming the border has achieved pacification due to his strength. Indeed, Trump very well may credit his current threat of tariffs with “forcing” Mexico to make the lower numbers of border crossings a reality.

It’s deeply disturbing that Sheinbaum’s statement—which appears partly directed at Americans—represents a far more faithful effort to inform us about the reality of the cross-border situation than anything offered by our own incoming president. It all suggests we may not be prepared for the gale-force agitprop that’s about to hit us.