When President Obama comes to Belfast, he's expected to praise a country at peace and call for walls that separate Irish Catholics and British Protestants to come tumbling down.

Barely a 10-minute walk from where the U.S. leader is speaking Monday, those walls have kept growing in size and number throughout two decades of slow-blooming peace. Residents today on both sides of so-called "peace lines" — barricades of brick, steel and barbed wire that divide neighborhoods, roads and even one Belfast playground — insist the physical divisions must stay to keep violence at bay.

Belfast's first peace lines took shape in the opening salvos of Northern Ireland's conflict in 1969, when impoverished parts of the city suffered an explosion of sectarian mayhem and most Catholics living in chiefly Protestant areas were forced to flee. The British Army, deployed as peacekeepers, erected the first makeshift barricades and naively predicted the barriers would be taken down in months.

Instead, the soldiers' role supporting the mostly Protestant police soon inspired the rise of a ruthless new outlawed group, the Provisional Irish Republican Army, committed to forcing Northern Ireland out of the United Kingdom and into the Republic of Ireland.

For all the unlikely triumphs of Northern Ireland diplomacy since the U.S.-brokered 1998 Good Friday peace deal — a Catholic-Protestant government, troop withdrawals, police reform, and disarmament of the IRA and outlawed Protestant groups responsible for most of the 3,700 death toll — tearing down Belfast's nearly 100 "peace lines" still seems too dangerous a step to take.

"I'd love to see that wall taken down and I could say hi to my neighbors, but it isn't going to happen. There'd be cold-blooded murder and I'd have to move out," said Donna Turley, 48, smoking a cigarette at her patio table in the Short Strand, the sole Irish Catholic enclave in otherwise Protestant east Belfast.

Right behind Turley's backyard refuge towers a 50-foot (15-meter) wall. It starts as brick, transitions into fences of corrugated iron, and is topped by more steel mesh fence. Each layer marks the history of communal riots like the growth rings of a tree. Higher still, two batteries of rotating police surveillance cameras monitor Turley and her Catholic neighbors, as well as the Protestant strangers living, audibly but invisibly, on the far side.

"It's terrible looking. But I wouldn't feel safe if it wasn't there. I couldn't imagine that wall being torn down. Nobody here can," said Tammy Currie, 21, who is Turley's nearest Protestant neighbor, standing in her own small cement patio backed by the wall. Her 3-year-old son jumps on a trampoline that a few months ago had to be cleared of shattered beer bottles thrown from the other side.

Both families rent state-subsidized homes provided by the Northern Ireland Housing Executive, which is responsible for making their homes as safe as possible from the risk of further rioting. That means both have triple-layered Perspex windows that are foggy-looking and unbreakable, and metal-tiled roofs that can't be set on fire.

It was a lesson hard learned. The Protestants of Cluan Place and the Catholics of Clandeboye Drive used to be able to look, from upper floors, into each other's back yards until 2002, when militants on both sides sought to drive each other out with homemade grenades, Molotov cocktails and even acid-filled bottles. An IRA gunman shot five Protestants, none fatally, while standing atop what was then only a brick wall. Most homes in the area were burned, abandoned and rebuilt, and British Army engineers doubled the height of the wall in 2003. Nobody's been shot there since, even though both sides continue to host illegal paramilitary groups billing themselves as community defenders.

This stretch of wall connects with other security lines that date back to the early days of the modern Northern Ireland conflict in 1970, when IRA men in Short Strand shot to death three Protestants allegedly involved in attacking the district's lone Catholic church. To make it less of an eyesore, Belfast City Council has funded imaginative art works all along that stretch, but it still leaves Short Strand looking a bit like Fort Apache.

Last month, the Catholic and Protestant leaders of Northern Ireland's unity government announced a bold but detail-free plan to dismantle all peace lines by 2023. British Prime Minister David Cameron formally backed the goal Friday. Obama is expected to do the same Monday.

The politician working closest to the Cluan-Clandeboye wall, Michael Copeland, says both G-8 leaders are out of touch.

"Removing the walls would be a catastrophic decision," said Copeland, a former British soldier and a Protestant member of the Northern Ireland Assembly, who keeps his office just around the corner from Cluan Place.

"The biggest walls to be addressed are in the minds of the people. And what people in here remember is being shot at, being bombed, having their street burned," Copeland said while sitting on a Cluan Place bench outside one resident's home. He knows everyone living in all 23 homes on the Protestant side and, in fact, helped get many of them get their housing assignment.

"The walls will come down when the people who live in the shadow of these walls, and look to those walls for a sense of security, can feel secure without them. Memories will have to fade. It will take another generation at least," he said.

The two sides mark their cultural divide in ways petty and profound. Each morning, two sets of children depart in different directions, wearing different uniforms, as Catholics head for their own church-run schools, the Protestants for state-run ones. At night, the two sides usually order fast-food deliveries from their own areas, fearful that someone from "the other side" might spit in their food. They use separate taxi companies and favor different newspapers.

Short Strand's community association has erected house numbers bearing each family's name in Gaelic, the little-used native tongue of Ireland that is loathed by most Protestants.

Reflecting their anxiety that the faster-growing Catholic community wants to push them out, the Protestants of Cluan Place have painted the gable end of one house with a mural featuring a massive Union Jack and a list of attacks on their street since 2002. "Still loyalist, always British, no surrender," it says.

The house opposite Currie's, belonging to an aunt, has a dog strutting about sporting a Union Jack collar, and Ulster loyalist music blaring loudly enough from a stereo to carry to Catholic ears beyond the wall.

Across the divide, 56-year-old Maggie McDowell cocks an ear at the sectarian tune. "Och, him again," she said, identifying her Protestant neighbor not by a name or face she's never known, but by his musical taste. Unlike most living on both sides of this wall, she was here for the 2002 rioting — and credits the wall's extension with ensuring no repeat.

She and her husband, James, keep a collection of the most interesting objects that have crashed into their house or back garden, including one smooth stone used as a doorstop. He points out holes in their home's brick wall marking strikes from past violence. Golf balls, a favored weapon for both sides, she collects by the bucket to give every so often to her golf-enthusiast brother.

When asked if she'd like the wall to come down, Maggie McDowell said, "It's a terrible thing to say, but I wish they could make it higher."



Maps and data of Belfast peace lines, http://bit.ly/11odl3w