The US presidential election is ramping up and polls continuously show illegal immigration at or near the top of the critical threat to America list.

This topic has been prevalent throughout the course of human history. We have employed diverse methods to address the problem of unwelcome individuals with harmful intentions. The construction of different forms of barriers has been the most common. The Walls of Babylon, Hitler’s Atlantic Wall, the Berlin Wall and the Great Wall of China are just a few examples that come to mind.

The walls and border technologies employed by nations today would have been inconceivable to our predecessors. Presently, there exist more than 50 border walls across the globe, each equipped with a wide array of technology.

The US-Mexico land border contains a whole host of imposing technology. Towers located throughout the 1,954-mile land border contain high resolution cameras and seismic sensors to detect movement and underground tunnels. Often this is combined with America’s AI system called Lattice that can autonomously identify, detect and track “objects of interest” from as far as 1.74 miles (2.8km) away. Another notable and useful tool, also used by the Frontex border agency of the European Union (EU), can capture people’s cell phone signals, providing their location.

The airspace around America’s southern border is also heavily monitored. This is achieved via drones, big and small, as well as the latest generation manned helicopters. Pilots for organizations like the Texas Department of Public Safety (DPS) and US Customs and Border Patrol (CBP) fly the impressive short range, turbine powered Airbus H125 helicopter. It’s an ideal aircraft to perform aerial patrol and surveillance missions, especially when equipped with a multitude of sensors and night vision googles.

All the above generates data, which America’s analytics tool Raven uses to provide situational awareness. Raven, or the Repository for Analytics in a Virtualized Environment is a data-mining tool used by US Immigration and Customs Enforcement (ICE) that enables its users to analyze trends and isolate criminal patterns for a variety of different and evolving missions.

The US and Israel have periodically worked together to develop many of these border defenses. In 2021, the Israel Defense Forces (IDF) and Israel Aerospace Industries (IAI) took additional measures to secure their border and released a new semi-autonomous robotic system called Jaguar. This robot Jaguar’s bite is a 7.62 mm MAG machine gun. It also comes equipped with high-resolution cameras, a remote-controlled public address (PA) system, and can self-destruct if needed.

American technology is present in various parts of the world, including the border between Greece and Turkey. To prevent the entry of unwanted migrants, Greek authorities have utilized advanced sonic weapons. Also labelled as sonic devices, sound cannons or the more official sounding Long Range Acoustic Devices or LRADs, the technology was originally developed by the US military in the 2000s. It’s an example of a “nonlethal” border technology albeit a highly controversial one.  For example, the Genasys’ LRAD 450XL emits sounds up to 150 decibels. This is a similar noise level to a shotgun going off right next to your ear. It’s capable of causing permanent hearing loss, as well as severe pains to the human body. Because of this, the European Union (EU) expressed concerns over Greece’s use of the device that “should conform to European fundamental rights, including the right to dignity.”

In Asia, the Indian government’s Border Security Force (BSF) have constructed walls so advanced that they cannot be seen. The CRON intrusion detection system is based on infrared array, which is invisible. The system, developed by a New Delhi based headquartered company, helps protect the 198 km India-Pakistan international border. India finds it more effective and reliable compared to their already advanced satellite monitored laser walls. These lasers are visible, think Tom Cruise in Mission Impossible dropping down on cables while trying to avoid the lasers. However, terrain and alignments can cause issues for the laser walls.

One border project that is less technological, but still grand in its own right is the wall Kim Jong Un’s regime secretly built during the COVID pandemic. North Korea’s 304 mile (489km) wall along the border with China contains concrete walls, watchtowers, double fencing and barbed wire to cut off routes used by both defectors and smugglers. Human Rights Watch is concerned the wall and overall security: “imposes overbroad, excessive, and unnecessary quarantines and restrictions on freedom of movement and trade, which have worsened the country’s already grave humanitarian and human rights situation.”

There have been similar concerns over Texas’ use of razor wire and buoy barriers at their Mexico border. Texas Governor Greg Abbott sees a “massive reduction” in migrant flow in the areas like Eagle Pass, Texas.

The effectiveness of these barriers, advanced or not, is therefore thrown into question. Despite the Great Wall of China’s grandeur, it failed to deter Genghis Khan and numerous tribes from infiltrating. Some invaders cleverly circumvented certain sections of the wall or devised alternative means to breach it. Israel’s more modern US$1.1 billion-dollar “Iron Wall” was penetrated by Hama’s terrorists who used bulldozers and cheap drone dropped munitions to get through.

Anticipate further development of humanity’s forthcoming walls and border security technology. Effective or not, these barriers will persist as clear signs to those outside that they are not entering legally.

Expect the difficult topic of illegal immigration to remain. How do we safeguard our borders that maintain our sovereignty and prevent unlawful activities, but also properly encompass the well-being of individuals who need assistance and are willing to work via the proper legal channels? At the end of the day, we are compassionate beings. We must extend our assistance to those who are hardworking, pose no threat and are genuinely in need.

Scott Firsing PhD is a 2024 Candidate for the Texas House of Representatives (West Austin). An Aviation and International Relations Scholar, he is a former Professor at The Citadel, Monash University and the University of North Carolina, and a graduate of Rutgers University and the London School of Economics and Political Science. Dr Firsing has appeared on Al Jazeera, BBC, CNBC and others, and his insight can be found in AP, Huffington Post, The Conversation, US News and World Report and other publications.