Turning the clock back to the 1980s, the open trade policies, free markets and economic liberalism were first adopted and upheld by then US president Ronald Reagan in coordination with the British Prime Minister Margaret Thatcher. These approaches resulted in shaping a global policy that brought about new trends in globalisation.

But these have begun to diminish in their impact, especially with the inauguration of the current US president, Donald Trump, and Theresa May, the British Prime Minister. The current Anglo-Saxon approach, in fact, promotes protectionism, and sacrifices achievements that were once for granted such as the UK being in the European Union and the US backing the Trans-Pacific Partnership trade deal.

Now, there is also a move towards cancelling similar deals with Canada and Mexico under the North American Free Trade Agreement (Nafta). But worst of all is the US government’s decision to build a wall along its borders with Mexico at a likely cost of $10 billion (Dh36.73 billion), which could result in economic implications on both sides.

Ostensibly, the end goal of the wall is to prevent illegal migration. And this was the very reason that led to the infamous Berlin Wall in the early 1960s, built to prevent the movement of people between the two parts of the German capital based on directives from the former Soviet premier Nikita Khrushchev. At the time, the wall hindered trade activities between both parts of the city.

Obviously, the construction of walls have become over the course of the past two decades a widespread strategy. Israel, for example, divided the West Bank into small parts by installing walls and barriers that turned life in Palestine into a living hell and destroyed several small projects that were dependent on movement between cities, thereby affecting business life and daily transactions of individuals and institutions alike.

However, history clearly tells us that walls are inadequate and do not work as they, without a doubt, do not thwart illegal migration. Instead they confer huge losses for the countries involved, help black markets thrive and lead to smuggling mafias that generate significant gains through bypassing the walls. These activities would as a result reduce the importance of walls in spite of their huge costs.

But what will happen if the US-Mexico wall is completed, always bearing in mind it is strongly opposed by Mexico? First, illegal trade — including drugs smuggling — will flourish by resorting to new routes such as underground tunnels, which will also help illegal migration.

Hundreds of tunnels will be constructed and they will be hard to control, as can be noticed from the underground tunnels between Gaza and Sinai peninsula. This border extends to a few kilometres, unlike the one between the US and Mexico which stretches more than 3,000 kilometres. Therefore, the expensive wall will be ineffective.

Second, Trump intends to cancel the free trade agreement with Canada and Mexico, meaning new custom duties will be imposed on trade between the countries, generating huge revenues for the US Treasury.

And with that being done in conjunction with the construction of the wall, smuggling of goods will increase, depriving the countries of revenues that could be generated from custom duties.

Third, none of the previous experiments in building walls made up a practical solution for controlling illegal immigration and drug smuggling. They, instead, obstructed trade and created social and psychological barriers that fuelled tensions and made an excuse for drug mafias to operate, resulting in economic consequences.

Yes, there are modern alternatives for monitoring and controlling borders by employing sophisticated techniques without disadvantaging economic, trade and social relations. It is also by regulating the movement of individuals in cooperation with all concerned parties that the issue of clandestine migration and drug trafficking can be mitigated.