I’m standing looking at a twenty foot high fence that at night is lit as brightly as daylight. It snakes away over dry hills to both east and west like a vulgar, modern version of the Great Wall of China. I’m in Nogales, a town in both Arizona and Mexico that is sliced in half by the fence. This is the border between the rich and poor worlds.

We’ve been talking to a young officer from Border Patrol. He’s responsible for about half a mile of the border. He sits in his van from 6 am to 2 pm every day waiting for “jumpers,” people making a break for the rich world. At the moment there’s about one jumper a day, and when I ask if he catches them he says I should talk to his superior. “Mostly, I’m a deterrent,” he says. His white van is covered in iron caging for protection for when he’s “rocked,” when people hurl boulders over from the Mexican side. He’s from Texas, has been in the job for a year, and hasn’t been rocked.

As we talk, very loud rap music with a heavy bass begins to come out of the Mexican house we are looking at, which is perhaps three yards from the other side of the fence. “That’s for us,” says a colleague. I imagine that it says “Up yours, gringos.” Behind us is a beautiful view of the mountains of Southern Mexico. When the fence was first built it was solid, but that was much less secure than the present fence, which is effectively huge railings and can be seen through. The officer can see the jumpers coming. In downtown Nogales the houses are even closer to the fence, and at one point the solid fence caused terrible flooding on the Mexican side because heavy rain couldn’t drain away as it had done for millennia.

I think of other walls and fences. I’ve seen similar fences in Belfast. I crossed the Berlin Wall in 1982 and remember the worldwide jubilation and excitement when it came down in November 1989. I’ve not seen it, but perhaps the most terrible of all these fences is the one that separates Israel and Palestine. I think too of the many prisons I visited in the early 80s. High fences mean prisons, and I wonder which side of this fence is the prison.

The border officer is the first line of defence, but there are at least two more behind him. Most of the migrants don’t jump, rather they come across the desert, often in large, organised groups. Earlier in the morning we drove to the point west of Nogales that is currently the most popular route. The routes change in an endless game of cat and mouse between the migrants and Border Control. What strikes me is the still beauty of the spot. The desert is not flat but rather rolling hills with mountains closer to the border. It’s not empty desert, rather it’s filled with cactuses and dry shrubs.

It may be beautiful, but it’s also lethal. We are about 12 miles from the border, and the migrants who cross this way have to walk for a day and a half before they even reach the Mexican side of the border. For most of the year the desert is baking during the day and cold at night, and it’s very disorientating, making it easy to get lost.

Many of those who try to cross are ill prepared. They come from Central America and Chiapas and Oaxaca in Southern Mexico. They are used to jungle not desert. Sometimes women start wearing high heels. In the last year there have been just over 200 deaths, but many bodies go undetected. My colleagues tell me the story of a grandfather resident in the US whose daughter and grandson tried to cross. The daughter died, and the grandson, dehydrated and delirious, was picked up by the Border Patrol and deported. The grandfather couldn’t bear the idea of his daughter’s body lying unburied in the desert and so began a search for her with friends. They searched for six weeks and found four other bodies before they found his daughter’s body.

I try to imagine how desperate you must be to attempt such a crossing. And even if you get as far as the road where we’re standing you may still be caught. As we drive back from Nogales to Tucson we are stopped and have to show our passports. And anybody in Arizona committing an offence at any time, perhaps jumping a stop light, can be asked to show their documents. If they can’t produce them they are deported straight away or jailed and then deported. More people have been deported during Obama’s presidency than during Bush’s second term, explaining one reason why Obama is not popular with Hispanics, who voted for him overwhelmingly in 2008.

My friends tell me the story of an “undocumented” woman who had been in the US for 32 years and has four children. She was picked up for “behaving suspiciously” and is facing deportation. She might be deported to anywhere along the 2000 mile border, and the border towns are filling up with the deported. They are some of the people most desperate to get back—to rejoin their families.

The possibility that you might be stopped at any time has created a lot of fear in Arizona. Even those who are fully legal may be fearful. I understood something about this in a tiny way when my wife and I arrived in the US this time. We flew into Dallas Fort Worth and had a three hour stop over before our connection to Tucson. We stood in line for almost two hours and began to fret that we’d miss our connection. We asked somebody to help, and he took us to the front of a line. When called we went forward, but the officer was immediately hostile.

“How did you get there?”
“One of your assistants put us there.”
“He’s not allowed to do that. Why did you get put forward?”
“We thought we might miss our connection?”
“That’s not our problem. You should have made a more sensible booking.”
“But other people connections were moved up the line,” I said rather pathetically.
“Look I’m here every day. I know the rules. That’s not allowed.”

He continued in this bullying vein for quite some time. It clearly gave him pleasure. We stood there like guilty children, feeling very powerless. It was tempting to say, “Look, sonny, we’ve stood here for two hours watching endless repeats of a facile video with people welcoming us to America. You have twenty booths with only three staff, and when we finally get to the front of the line, directed by one of your staff, you tell us off and bully us. You are no doubt taking out on us the inadequacies of your self, life, and relationships, for which we feel sorry, but this is no way to welcome people to America.”

We would, of course, have been sent straight home and perhaps banned from entering the US again. So we smiled weakly and looked at our feet. If this is how we feel—rich gringos, laden down with degrees, able to speak English, and entering the US legally—how can poor undocumented migrants with little English feel.

But some people are bolder. My colleagues told me the story of a Mexican woman who lived legally in the US for decade and had 11 children, all US citizens. She was fierce, knew her rights, took no nonsense from anybody, and was all about helping others. She lived on the border and went back to a time when it was easy to go backwards and forwards across the border.

She helped out in an orphanage, and one day was taking a pile of clothes to the children. Both the US and the Mexican officials told her it was not allowed to take used clothes into Mexico. Her response was to walk a little way down the road, ring the orphanage on her cell phone, and then start throwing the clothes over the fence. Nobody stopped her.

Two years later she died, and a staunch and traditional Catholic she’d made it clear to her children, mostly daughters, that she wanted to be buried on the Mexican side within 24 hours of dying. Her daughters tried getting the necessary papers to take a body across the border but were told it was impossible within 24 hours. They were, however, like their mother, and undeterred in three cars they took their mother’s coffin to the border. The officials asked for the papers but were told they didn’t have them. Then you can’t cross, said the officials.

At this point the daughters, dressed glamorously in black suits with black high heels and thick scarlet lipstick, grabbed their mother’s coffin and ran across the border. I imagine this as the opening scene in a Francis Ford Coppola film, and it’s an image of the border that I prefer to the young border officer staring at the fence eight hours a day waiting for jumpers.

Competing interest: RS was visiting the US Mexico Border as part of his job as director of the UnitedHealth Chronic Disease Initiative. Together with the National Heart, Lung, and Blood Institute, the initiative has 11 centres in low and middle income countries, one of which is based in Hermosillo, Sonora, Mexico.