It matters little what they are called - walls, barriers or fences - the intention is the same: to redefine human relations into "us" and "them".
The Walls of Shame series is about division, and about the barriers that men erect, in calculation or desperation, to separate themselves from others, or others from them. When diplomacy and conciliation fail, this is the alternative, and not since medieval times have walls been so in demand around the world.
Tens of new walls, barriers and fences are currently being built, while old ones are being renovated. And there are many types: barriers between countries, walls around cities and fences that zigzag through neighbourhoods.
This series looks at four examples of walls around the world. It examines the lives of those who are living next to them and how their lives are impacted. It also reveals the intention of the walls' designers and builders, and explores the novel and artistic ways walls are used to chronicle the past and imagine the future.
Taking its name from John F Kennedy's reference to the Berlin Wall in his state of the union address in 1963, this series examines four walls: the one on the American-Mexican border, the West Bank wall, the Spanish fence around Ceuta, and the walls inside the city of Belfast in Northern Ireland.
The US-Mexico border wall: The great wall of America
A border of more than 3,000km separates the US from Mexico - but it is defined not only by physical barriers made of concrete and steel but by an immigration policy which is failing to address the issues behind illegal migration.
Although the US has spent billions of dollars on border enforcement, the lure of work sees illegal migrants enter the country at a rate of 850,000 a year.
A series of walls along the Mexican border were designed to stem this flow but based on current estimates it has failed. Instead, the walls have re-routed human traffic into remote desert areas where people risk their lives in deadly conditions attempting to enter the US.
This film shows what US immigration policy looks like on the ground for the people making the perilous journey for a better life, and for the Americans who call this borderland home.
Update: Since this film first aired on Al Jazeera English in 2007, the US continued to increase spending on border security. At no other time in history have there been as many border patrol officers on duty as there are today.
And now the authorities are bracing for a new challenge: children. Since 2014, the number of families and unaccompanied children apprehended at the border keeps skyrocketing.
Young people are filling family detention centres near the border, having fled poverty or extreme violence in Central America.
And today the issue is taking centre stage in this US presidential election, with Donald Trump calling for more walls, leading some migrants to say they will cross the border now before it may be too late.
Source: Al Jazeera