In all of history, there has never been a border anywhere in the world that was impenetrable. The Great Wall of China wasn't, neither was the Berlin Wall and especially not the so-called Iron Curtain, which split up Europe with a series of fences, mines and watchtowers manned by guards with orders to shoot to kill. Physical barriers dividing neighbors are everywhere across the planet. However none are successful, all are reminiscent of the Middle Ages and they do not represent the 21st century.

Some are simple walls and fences. Others are more sophisticated, bolstered with motion detectors, infrared cameras, X-ray systems, night vision equipment, drones and even helicopters. You can find them in places like India, Afghanistan, Spain, Morocco, Thailand, Malaysia, Saudi Arabia, Baghdad and, of course, along the stretch of Mexico's border where Trump promises the wall, which exists only in his imagination, will be "tall, powerful [and] beautiful."

His wall, which is pure demagoguery, is the total fantasy of a loudmouth who heinously called Mexicans rapists, criminals and even snakes, just to incite anger and win over followers. It is amazing that this country, which in 1989 sought to bring down the wall that divided Germany, today has half of its population enthusiastic with the absurd notion that sealing the border will stem the flow of immigrants, both those looking for work and those who want to spread terror.

The United States has a northern border with Canada and a southern border with Mexico, which when combined are more than 7500 miles long with 12,500 miles of coastline and an immense network of airports, seaports and other points of entry. It is completely unrealistic that a wall would stop all terrorists, undocumented persons, narcotics or contraband. Nowhere in the world is there a border that is 100 percent secure; there never has been and there never will be. Just as former Secretary of Homeland Security Janet Napolitano stated, "If you build a 50-foot-high wall, somebody will find a 51-foot ladder."

The wall Trump says he is going to build along the 2,000 mile Mexican border will include, according to him, the most cutting-edge technology. The problem is that it will require 10 percent of all the cement produced in the U.S. and would cost nearly $25 billion, or, In other words, a fourth of what the federal government spends annually on domestic infrastructure. And if Mexico has already said it will not pay for the wall, where will the money coming from?

The country has more urgent needs: repairing or investing to not just modernize but also to stop the deterioration of bridges, highways and rail systems that are on the verge of collapsing and cannot compete or be on the same level as other industrialized nations. Ironically, his proposal for a wall that keeps Mexicans out, which has excited the conservatives so much, comes from a political party that heaps criticism on debt and governmental spending.

Trump ignores the fact that Mexicans are no longer coming into America in large numbers. In fact, in the last decade, more have left than have entered. This is partly due to a lower birthrate in Mexico, but mostly because of the weak U.S. economy that no longer guarantees employment or a better life.

The Republican hopeful says that once he is in the White House, he is going to deport 11 million undocumented people. What he has yet to say is how he will do it; first finding them and then sending them back. The current 5000 migration agents, or even the 15,000 he wants to have, cannot go down the street asking who has papers and who doesn't. It takes a court order to arrest them, a trial to deport them and at least 12 agents to go and search for each person in his/her home. The numbers just don't add up for Trump.

But if by some remote chance those undocumented persons are found, how are they going to be removed? Estimates have been made that a minimum of 200,000 buses would be needed; where are they going to be parked and where are they going to be sent? Obviously, not all of the would-be deportees are from Mexico. But they are all part of a silent yet crucial part of life in the U.S.