On the Tuesday after Donald Trump's January inauguration as president of the United States, journalist Jonathan Katz tweeted in reference to the unfolding spectacle: "First they came for the Latinos, Muslims, women, gays, poor people, intellectuals and scientists, and then it was Wednesday."

The days continue to progress in similar fashion. On the one hand, there's been the rapidly evolving horror of the Muslim ban. And on the Latino front, it seems that not even Mexicans in Mexico proper may be safe from Trump's reach.

According to the Associated Press, Trump recently informed Mexican President Enrique Pena Nieto that "you have a bunch of bad hombres down there" whose bad behaviour is not being properly addressed: "I think your military is scared. Our military isn't, so I just might send them down to take care of it."

Nothing like a casual threat of invasion to keep folks on their toes.

One finds oneself wondering whether a new and improved border wall might not be a fine idea indeed - but as a defensive measure against US incursions.

Extensions of ego

As Trump tells it, the "big, beautiful wall" he has ordered constructed along the US-Mexico border will keep out Mexican migrants, to whom he has previously referred in characteristic antiracist eloquence as drug dealers and "rapists".

Fox News has reported that construction of the wall alone could cost up to $20bn.

The project has met with opposition even from within Trump's own party - not on account of any ethical considerations, obviously, but rather owing to concerns over the cost and likely ineffectiveness of the migrant-stopping ploy.

Trump himself has made a show of insisting that Mexico foot the bill for the monstrosity, retroactively if need be.

In a recent dispatch for Fortune magazine titled "Trump Doesn't Really Care If Mexico Pays for the Wall", the Center for International Policy's Laura Carlsen explores possible motives for Trump's determined humiliation of the southern neighbour despite "not appear[ing] to actually expect Mexico to directly pay for the wall".

Beyond the ever-present possibility that the American head of state is merely "acting irrationally" and "wield[ing] executive power as an extension of his personal ego," Carlsen detects a variety of other potential explanations.

These range from the pursuit of increased leverage in a renegotiation of the North American Free Trade Agreement (NAFTA) to the encouragement of an enhanced Mexican security crackdown on Central American migrants entering from Guatemala, to the likelihood that Trump wants to "keep Mexico-bashing in the news and mobilise his base of supporters for further measures against migrants and Mexican trade and investment".

The 'security' business

Trump's ego is, no doubt, a pre-eminent contender on the contemporary world stage - an arrangement reinforced by the fact that he presides over a disproportionate percentage of the earth's wealth.

But there are plenty of other entities that stand to turn a handsome profit from his policy of unabashed xenophobia.

One of the ultimate functions of heavily fortified borders is to rally populations against a perceived enemy and thus redirect attention from national shortcomings and unsavoury behaviour.

These include but are certainly not limited to those in the business of border "security" - itself a misleading term designed to market the US-Mexico frontier as a de facto war zone as well as an existential battlefield in which American "greatness" is at stake.

The false advertising routine provides a convenient excuse for lucrative militarisation schemes.

You won't hear any complaints from drone manufacturers, for example, with regard to what boils down to a war on Mexican dignity - and the dignity of other refugees and non-elite migrants.

Age of irony

Meanwhile, it seems border walls have become an industry in their own right.

In one of the great ironies that have come to typify the current era, the Financial Times reported on inauguration day that "the biggest corporate winner" of Trump's border fortification venture "may well be a Mexican cement manufacturer": Cemex, whose shares had just "hit an eight-and-a-half-year high".

This is the same Cemex, incidentally, that - as the popular Electronic Intifada website has documented - has been complicit in the construction of Israel's apartheid wall as well as illegal mining activity on occupied Palestinian land.

When it comes to the profitability of exclusion, of course, the Israelis are masters of the trade - a position underscored by Israeli Prime Minister Benjamin Netanyahu's notorious tweet of 28 January: "President Trump is right. I built a wall along Israel's southern border. It stopped all illegal immigration. Great success. Great idea."

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The tweet occasioned some backpedalling from Israeli President Reuven Rivlin, who endeavoured to imply that Netanyahu wasn't really talking about Mexico.

In the meantime, Bloomberg News has noted in the most sanitised language possible that Magal Security Systems, the "Israeli company that fenced in Gaza" (ie, helped convert the Palestinian territory into the "world's largest open-air prison"), is angling for a hand in the Mexico wall.

One of the ultimate functions of heavily fortified borders is to rally populations against a perceived enemy and thus redirect attention from national shortcomings and unsavoury behaviour - which in the case of the US happens to entail the wanton violation of other people's borders, both militarily and economically.

If only we could look in a mirror rather than at a wall, that might indeed be a "big, beautiful" thing.

Belen Fernandez is the author of The Imperial Messenger: Thomas Friedman at Work, published by Verso. She is a contributing editor at Jacobin magazine.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.