When Donald Trump announced his candidacy for president in June 2015, he made a lofty promise. “I will build a great, great wall on our southern border.” For good measure he added, “And I will have Mexico pay for that wall.”
Trump’s promise (and subsequent actions as president) contains bravado, nationalism, and controversy. However, when you consider what a wall traversing Mexico would accomplish, it does not contain a cost-effective solution to Trump’s reactionary concerns with immigration.
There is not a border crisis
For example, a wall would not stop a border crisis because a crisis does not exist. The era of large-scale illegal migration by Mexicans to the U.S. is over. Today, in a phenomenon that began five years ago, most apprehended at the border are from Central America and are seeking asylum to escape violent conditions.
As a result of this shifting demographics, Border Patrol apprehensions along the Southwest border plummeted from a high of over 1.6 million in 2000 to around 300,000 in 2017 (an ~80% decrease). A 2017 Trump administration report from the U.S. Customs and Border Protection (CBP) boldly declared illegal entry in the United States had reached historic lows. “In FY17, CBP recorded the lowest level of illegal cross-border migration on record, as measured by apprehensions along the border and inadmissible encounters at U.S. ports of entry.”
Available 2018 figures suggested that illegal entry by family units continued to be low. According to additional Border Patrol reporting, apprehensions of family units who crossed the Southwest border illegally actually declined by 3% in the first eight months of FY 2018 compared to the same period year-over-year.
A wall is unlikely to work
Another reason why the wall would be ineffective is it would not likely deter crossing from a structural standpoint. While there are a handful of walls that are effective at sealing some parts of a nation’s border (like Korea, Israel, and Spain), these walls are short in length, built on flat land, and heavily patrolled.
However, history is littered with barriers that didn’t work. Hadrian’s Wall didn’t stop tribes from migrating south into the Roman Empire (the 72-mile barrier was too sparsely guarded). The heavily fortified Maginot Line did not deter German aggression in the runup to World War II (the Germans went around it, attacking weaker points of the French defensive). The Great Wall of China was also unable to keep out invading parties from the north (the most ardent of the wall-building dynasties, the Ming, collapsed as a result).
As they do today, anybody who wants to go around, under, and over the current wall/fencing that exists along the Mexican border will continue to do so even if the wall/fencing gets bigger and scarier.
Beyond the fact that most people who wish to get past a wall will find a way to do so, there’s this: According to a Center For Migrations Study 2017 report, nearly 60% of undocumented immigrants in the U.S. came legally on a tourist visa and then overstayed. A wall will do nothing to stop that.
A wall would be difficult to construct and expensive
Finally, construction of the ineffective wall would be both difficult and expensive.
Since much of the required land is in private hands, building the wall that Trump envisions would entail extensive and aggressive use of the government’s powers of eminent domain. That alone will take many years and billions of dollars.
Additionally, much of the border presents serious geographic obstacles to wall-building, including rivers and mountains. This includes the Rio Grande, a river so large that the Spanish explorers literally named it “Big River.”
When you add it all up, a reasonable estimate for the wall’s ultimate cost is somewhere in the range of $25 to $50 billion. That’s before considering maintenance and staffing, which will add billions more annually.
There are many more reasons the wall would be bad ranging from the environment (it would interfer with the natural migratory patterns of various animal species) to the economy (a five-hour disruption of the U.S.-Mexico border near San Diego last November cost local businesses $5.3 million in lost revenue). However, it’s already clear that a wall is a waste of national resources.
A better strategy would be to cut off the supply of asylum seekers by working to improve the lives of those in Central America by improving security, reducing political corruption, addressing climate change, and increasing economic opportunities.