The resurgence of fortified landscapes in West Africa - African Networks Lab

West African states respond to insurgencies by building city walls and fortifying borders. These initiatives aimed at controlling the movement of jihadist groups are a double-edged sword. While they provide short-term protection, they can also deepen rural insecurity and civilian vulnerability.

By Olivier Walther and Steven M. Radil, 4/28/2026.

The new fortresses

In August 2024, militants from Jama’at Nusrat al-Islam wal-Muslimin (JNIM) attacked residents of Barsalogho, a town in north-central Burkina Faso, as they dug a 20-kilometer defensive trench.

The Burkinabe soldiers and self-defense volunteers guarding the construction site retreated, leaving approximately 300 unarmed civilians to be killed. It was the worst single attack in the country’s history.

Barsalogho is one site in a much larger pattern. Over the past fifteen years, West African governments, local communities, and international donors have built hundreds of kilometers of earthen fortifications to slow jihadist incursions.

Our analysis shows that sand berms up to three meters high now encircle most major towns in northeastern Nigeria and the Lake Chad basin.

Cameroon has also fortified nearly 200 kilometers of its border with Nigeria while Togo has built over 36 kilometers of defensive works along its frontier with Burkina Faso and Benin.

Whether around a town or at a border, these structures are designed to stop highly mobile fighters, to channel traffic through fortified gates, and to prevent suicide attacks.

The fortification of West African territory has few modern precedents, but it has deep historical ones. In the precolonial era, cities, villages, and individual house clusters defended themselves with earthen walls and mountain refuges against raiding and political fragmentation.

Most of these structures disappeared during the twentieth century as colonial and postcolonial states consolidated control. They are now being rebuilt.

Protecting cities

Most fortifications in the region are built around entire cities and take a circular shape, as in Kauwa, Nigeria, shown below. Their size is often considerable. The berm surrounding the city of Pama in Burkina Faso has a circumference of 15 kilometers. The one around Maiduguri, more than 65 kilometers.

Deep trenches are also built around power stations, government offices, schools, and hospitals. Even strategic crossroads are surrounded by rings of earthworks, as along the Gubio-Damasak road in northern Nigeria.

When fortifications protect military camps or forward operating bases, they are generally accompanied by bunkers and tanks and take a square shape, as in Assighassia in Cameroon below.

The double berm of Kauwa, Nigeria (left) and a military fort guarding the Cameroon-Nigeria border south of Assighassia (right). Source: Google Maps (Kauwa and Assighassia), 2026.

The primary role of these structures is to slow offensives by militants who use highly mobile vehicles such as motorcycles and pickup trucks. By forcing attackers to dismount, the defenses guard against suicide attacks, which have killed nearly 4,500 people in West Africa from 2011 to 2024, according to ACLED.

On 6 April 2022, for example, Boko Haram militants parked their motorcycles behind a trench dug around the town of Damboa in Nigeria and entered on foot, setting part of a primary healthcare center and a technical girls’ college ablaze.

Around cities, the moat dug outside the berm prevents attackers from using the barrier to take up positions with heavy weapons, particularly the machine guns mounted on light vehicles, or “technicals,” that are ubiquitous in the region.

Earthworks also allow government forces to channel traffic through a small number of fortified gates, where travelers’ identities are verified through numerous checkpoints.

Our analysis of satellite imagery shows that fifty major earthworks have been built in northeastern Nigeria and around Lake Chad.

All urban agglomerations with more than 10,000 inhabitants are surrounded by earthworks long enough to be visible on satellite images, as shown below.

City fortifications in northern Nigeria and Lake Chad region, 2026. Source: authors based on Google Maps and Africapolis. Cartography by the authors.

The exceptions are towns abandoned following battles between the government and jihadist insurgents, such as Fage (Kirenowa), Ngurno and Abadam, or towns protected by bodies of water such as Baga Sola.

The perimeter of these fortifications is estimated at 560 kilometers. If we include the defensive trenches within urban areas as well as those built in smaller towns, the total length is likely to reach 700 kilometers, corresponding to the distance between Maiduguri, the largest city in Borno State, and the Nigerian capital of Abuja.

In many cases, several generations of walls have been built, each set further from the city center. The most imposing structures are...