EL PASO, Texas » At the foot of a bridge that helps bind El Paso and Ciudad Juarez, a U.S. Border Patrol officer warns two pedestrians not to stray once they reach the Mexican city. Stay on the main road. Avoid side streets. Very, very dangerous city. OK?

The pedestrians nod and join the back-and-forth human flow between one of the safest cities in the United States and one of the most violent in the world—getting worse by the month. Including a pause to take in the Rio Grande, here just a muddy stream with a boastful name, their walk takes five minutes.

On the other side, boyish Mexican soldiers stand about, weapons in hand. Men linger before tired and empty storefronts. Beggars pull at your coat. Then a taxi driver steps up to ask if the visitors need a ride to the morgue.

A legitimate question, perhaps, in a city whose latest massacre—16 dead, most of them teenagers—occurred just two weeks ago. A city with nearly 250 homicides last month; about one every three hours. A city where homicides have jumped from about 300 in 2007, to about 1,620 in 2008, to about 2,660 last year.

The visitors decline, and take the five-minute walk back to another world.

At night, from above, the lights of El Paso and Juarez seem to blend into a single urban constellation, and the Rio Grande separation disappears amid a million grounded stars, each one pulsating with someone's story. It has been this way for generations.

But the drug-cartel war that broke out in Juarez two years ago, killing thousands and giving birth to a general air of lawlessness, has clarified the muddy Rio Grande as the divide between violence and peace. And El Paso has become a kind of sanctuary city, for the businesses and people and even the culture of Juarez.

El Paso, with a population of 740,000, and Juarez, with one of 1.4 million, have long been urban sisters, as tens of thousands of people move between the two every day, to work, or shop, or visit. But the cartel war has complicated things here: The violence in Juarez can seem so far away, and yet so close.

Here is Carlos Spector, 54, an immigration lawyer with dual citizenship who once had both an office and a television show in Juarez. But after receiving threats from the Mexican military, he says: “;I just don't go. I cannot go.”;

Spector has at least 10 clients seeking asylum in the United States because the wholesale violence in Juarez—where freelance criminals now seem to act with impunity—has them distrusting their government, their military, their neighbors.

Just the other day, Spector says, engineers from Juarez told him that masked men had come to their office to extort money. When they complained to the police, he says, they were told to “;scratch your back with your own nails.”; In other words: Go to El Paso.

Here, too, is Omar Herrera, who with two brothers recently opened Maria Chuchena, one of the many sleek Juarez restaurants resurfacing in El Paso. Sitting in a booth as the transporting voice of the singer Shakira surrounds him, he recalls how business in Juarez plummeted after the drug war began.

Now, Juarez's once-bustling Lincoln Avenue, where the first Maria Chuchena opened and thrived, is deserted; the only glow, he says, is that of a solitary ATM. And the Maria Chuchena in the city of Chihuahua, 230 miles south of here, was burned down, he says, probably as a warning to anyone reluctant to pay tribute.

The brothers did not flee Juarez, Herrera points out, citing the Maria Chuchena that remains in the Campestre neighborhood—”;the Beverly Hills of Juarez.”;

Still, he often finds himself reminiscing about the vibrant Juarez of yesterday, and he is only 26.

“;No one in Juarez came to El Paso for anything,”; he says. “;It was the other way around.”;

And here in downtown El Paso is yet another Juarez light: A woman whose name will not be shared. A woman who, after telling her story, offers to show the scars that can be seen. She then lifts her shirt to reveal fresh confirmation of the bullet life in her home city, a few miles from where she hides.

She is 36, with eyes weary from weeping. Her husband, 40, studies his callused hands as she talks. Her daughter, 12, did not go to school again, and is in the bedroom; having seen her mother shot, the girl wants her close by.

The familiarity of the woman's Juarez story makes it all the more harrowing. A Wednesday evening. A working-class family relaxing in front of their home. Eating pumpkin seeds. Watching their kids play in a park across the street. Masked men with guns darkening the view. Gunfire.

Her brother: dead. A sister-in-law: dead. The sister-in-law's stepfather: dead. Though hit several times, the woman rolled under a pickup truck and played dead. The killers drove off with no sense of hurry, never to be found, leaving wailing in their wake.

The woman spent two months in a Juarez hospital, but her health continued to decline after her release. She was then admitted to the University Medical Center of El Paso, becoming one of 83 victims of Mexican violence treated by the hospital last year.

She stayed a month. All the while, her husband and her family slept in their van, in the hospital's parking lot.

Then Ruben Garcia, the director of Annunciation House, an El Paso organization that helps the “;peoples of the border region,”; received a call from the hospital. It was about to release a patient—this woman—with an open wound that required a portable drain pump that could not be taken across the border. Did Annunciation House have room?

The family now sits in the small living room of a spare apartment, still not clear what happened to them. They had a house, a mortgage. Gone. The mother sold items at flea markets; her husband was a woodworker. Gone. They were not involved in drugs, so—what happened?

Could it be connected to the killing their 15-year-old son witnessed a month earlier? Could it be a case of mistaken identity? When neighbors ask after them, is it out of concern or because information is money?

The husband shakes his head. He knows they are not here legally, and their chances of being granted asylum are slim. Still, he says in Spanish, “;We cannot go back.”;

Back to a house less than a half-hour's drive from where he and his family hide.

This is how it is now in El Paso.

On Doniphan Road, for example, a bar called 33 announces with a bright sign that it is “;100 (PERCENT) Estilo Juarez”;—100 percent Juarez style.

And on Mesa Street, a waiter in a new restaurant says that, yes, it used to be in Juarez, but was forced to close. “;Accident,”; he says, his fingers cutting quotation marks in the air.

Sitting in this same Juarez-chic restaurant, Benjamin Alire Saenz, a poet and novelist, points out the window. On Martin Luther King's Birthday, he says, he saw a young man standing right there, on Mesa Street, holding a sign that said, “;Family Kidnapped in Juarez—Need Help.”;

The only way that Saenz could process this disturbing image was by writing a long poem, angry and true. It ends:

I have a dream and you have a dream and everybody
has a dream something no no no that is the worst
thing to do write something beautiful beautiful
another lie on the border another beautiful lie
that will help us forget Juarez is alive and well
and living in El Paso.