Donald Trump's saber-rattling may or may not deter Kim Jong-Un, but it has had an effect south of the border.
In the first few months of this year, illegal border crossings have dropped precipitously, according to federal statistics and anecdotal evidence. It is an early proof of concept that, yes, it is possible to secure the border and a victory, even if a provisional and incomplete one, for President Trump's enforcement agenda.
Once you stripped away the bluster and impossibilities from Trump's rhetoric on immigration during the campaign - there wasn't going to be a wall along the entire border paid for by Mexico, nor were there going to be mass deportations and a Muslim ban - the irreducible core of his message was a commitment to crack down on illegal border crossings.
This is happening. It has been reported in the media, but it almost never makes it into the conversation about Trump's first 100 days in office, despite the fact that it is one of his central agenda items.
If Trump had promised to almost immediately reduce illegal border crossings from Mexico to a 17-year low, it would have been dismissed as characteristic Trump bombast. But here we are. On the border, there is cause to be, if not tired of, at least encouraged by all the winning.
According to the Department of Homeland Security, there were 17,000 arrests at the border in March, the lowest reported figure since 2000, and down significantly from nearly 60,000 arrests in December. The decline in the number of parents and children has been particularly stark, from 16,000 in December to 1,100 in March, even though the warmer weather typically brings an increase in migrants.
The evidence on the ground backs up the statistics. A week or so ago, the Los Angeles Times reported that it found a "once-bustling crossing point" along the Rio Grande "desolate."
Betsy Woodruff of The Daily Beast visited a shelter that has been operating in Northern Mexico for more than three decades serving migrants before they make the final leg of their trip into the United States. Typically, 100 or more migrants would sleep there on any given night. But there were fewer than a dozen at what is usually a heavily trafficked time of year.
The message has been received south of the border that Trump is, to coin a phrase, a bad hombre. His tough rhetoric alone would be enough to make migrants think twice about coming across the border. But the administration also has tightened up on enforcement. Immigration arrests and so-called detainers -requests to local law enforcement to turn over to the feds undocumented immigrants in jail - have both increased. Consequently, the equities involved in illegal immigration have changed.
The fees charged by so-called coyotes to bring people across the border have risen, reflecting the increased risk. A jump from, say, $3,500 to $8,000 represents an enormous new expense for a mother in Honduras, especially if her chances of staying in the United States are diminishing.
As a Border Patrol agent told the L.A. Times, "Are you going to risk a 1,000-mile journey and pay $8,000 to be smuggled if you're not sure you'll get to stay? I wouldn't."
The early trend at the border is a rebuke to the fatalists who have argued that it's impossible to reduce illegal immigration because it is the product of ineluctable economic forces. It is certainly true that jobs in the U.S. are a magnet. But the cost-benefit calculation undocumented immigrants make when considering whether to come here is obviously subject to change based on changing incentives.
Mexico and its southern neighbors haven't suddenly become better countries over the past several months. Nor has the U.S. jobs market become less alluring - indeed, it might be getting stronger. Enhanced enforcement, real and perceived, is clearly affecting the decision-making of would-be migrants.
Some caveats. First, the Trump administration will have to continue to strengthen enforcement if illegal immigration is not going to bounce right back to its normal trend. The experience after the 1986 amnesty confirms this. The law was supposed to include tougher enforcement measures, and this expectation suppressed immigrant flows. When it became clear that the enforcement was all talk, though, illegal immigration continued as before.
Second, visa over-stays who come here legally rather than sneaking over the border are a large contributor to illegal immigration. This trend deserves as much attention as the border.
Finally, the administration will have to resist the urge to declare victory and go home. The moderates in the White House may be tempted to soften Trump's image via a grand bargain on immigration, arguing that the decline in border numbers means it's "mission accomplished" on enforcement and time to pivot to a large-scale amnesty. Eventually, such a deal might make sense, although not before a durable enforcement regime has proved its effectiveness over several years.
What Trump has done so far on immigration is hardly radical and basically represents a return to the pre-Obama status quo, when the federal government didn't openly flout its own laws. As Homeland Security Secretary John Kelly rightly complained the other day, the media are constantly portraying the administration's enforcement as draconian, often based on incomplete or stilted reporting. The real story is that, for now, Trump actually has results.