Walls, fences and border barriers around the world, their functions and effectiveness

Walls, fences and border barriers usually serve to control the border, keep out undocumented immigrants, prevent smuggling, or have been erected when borders are disputed and unclear. Walls are, among others, on the borders of North Korea and South Korea, Hong Kong and China, South Africa and Mozambique, Botswana and Zimbabwe, Egypt and the Gaza Strip, Israel and the West Bank, Kuwait and Iraq, or in Spain. Walls or barriers also stand on the borders between Uzbekistan, Kyrgyzstan, Turkmenistan, Afghanistan and Kazakhstan, Saudi Arabia and Yemen, Saudi Arabia and Iraq, Malaysia and Thailand, Bulgaria and Turkey, and Hungary and Serbia. The longest border barrier between India and Bangladesh is approximately 3,268 km long.

As of March 2022, there were 74 border walls worldwide – most built in the last two decades – and at least 15 more were planned to be built. Meanwhile, after the end of World War II, there were fewer than five border walls in the world, and after the fall of the Berlin Wall and the end of the Cold War, fewer than a dozen.​ However, studies worldwide indicate that the direct and indirect costs of building border walls outweigh the benefits. As border enforcement increases, smugglers’ profits and the presence of organised crime increase. Border barriers separate previously interdependent economies and erode the social life of border communities. In addition, border walls are bypassed and breached.