BELFAST, Northern Ireland -- Angie Boyle tightly clasped the hand of her 10-year-old daughter Helen on the walk to school. A few streets away, Alyson Ross made a similar trip alongside 6-year-old Rachel.
The girls live in the same Belfast neighborhood, Ardoyne, and attend schools virtually side by side. They are unlikely ever to become friends.
The boys and girls at Rachel's Wheatfield Primary School are Protestants, the girls at Helen's Holy Cross Primary all Catholic. That separates them as surely as the rows of British armored cars and riot police that have kept the two communities apart since schools reopened Monday.
Behind the ugly confrontations -- which hit a low Wednesday when Protestant militants threw a homemade grenade toward girls and parents outside Holy Cross -- lie complex fears and furies that sustain Northern Ireland's conflict from one scarred generation to the next.
Each community considers itself the victim, the other the aggressor. The only thing they seem to agree on is the need to keep living apart.
"It's weird but true that you can tell somebody's religion by the side of the street they walk on," said Jim Boyle, Helen's father. Three members of his family served prison terms for Irish Republican Army bombings, and he says the Catholic majority in Ardoyne has long supported the IRA.
Ross, who lives in the much smaller Protestant section of Ardoyne, recalled how she learned the difference between "their" territory and hers.
"I remember the first time I ever walked down there, some of the Catholic boys asked me where I was from. When I said 'up the road,' they said 'This is not your area.' I'd never walk down there now. Too many people have had the face beat off them for trying," Ross said.
At the top of her street, a gaggle of tough-faced men stood beneath banners of the outlawed Ulster Defense Association.
"You certainly would never argue with them, you just keep your head down like an ostrich," Ross said. "But you do feel safer having them there, because you know their purpose is to keep the other side from coming up here and smashing up our houses."
The 1998 peace accord that was supposed to ease Catholic-Protestant tensions, and end each community's dependence on illegal gangs, has instead reinforced animosities in places like Ardoyne.
While Catholic expectations have never run higher, many Protestants see their world turning upside down. Their alienation is compounded by the reality that, in many places including Ardoyne, their community is retreating from a growing Catholic presence.
Into that explosive mix walked 150 Catholic girls, whose school had the misfortune to be built in 1969 -- just as Northern Ireland's conflict ignited -- on the Protestant side of Ardoyne.
Protestant mobs began blocking the front entrance to Holy Cross in June. They called it retaliation for Catholic attacks on their homes, which are separated in places from Catholic houses by high fences of brick and steel. They resumed their protest this week and vowed to keep it going until the Catholics leave them alone.
Catholics protested that their homes suffered much more frequent attacks from Protestant stones, gasoline bombs and grenades, a view backed by police statistics. They refused to use the school's safe back entrance.
"After 30 years of being treated like a second-class citizen, I'm damned if I'm going to be put in a situation where I have to tell my daughter that she's a second-class citizen," said Boyle.
"Some people say the parents are using the children, but they're not. We're all just fighting for what's right," said Helen Boyle, who like many young Catholics demonstrates a level of political sophistication rarely found on the demoralized Protestant side.
"I can't understand why the Catholic parents keep bringing their children into that situation," said Alyson Ross. "If the roles were reversed, I'd make sure my child took the back door. They must want their children to be bitter."
The police have found themselves stuck between bad choices. Whereas in June they made the Catholics take the back door, this week they clubbed the Protestants back.
Members of the UDA were in the vanguard this week as Protestants rained bricks, rocks and homemade bombs on the Catholics and the police.
The UDA killed several hundred Catholics before calling a 1994 truce, and its chief political spokesman, John White, served time for the slaying of a Catholic politician and his Protestant girlfriend.
Protestants pick out the senior IRA figures in the Catholic crowd beyond the police lines. Most Protestant fury has been directed at Sean Kelly, who killed nine Protestants in an IRA effort to kill the UDA's commanders in 1993. The bomb Kelly was planting also killed an IRA man.
In quieter times, the Wheatfield and Holy Cross schools regularly meet in arts programs and field trips, and Rachel says she has made Catholic friends. None has ever come to her house.
"It would cause everyone too many problems," her mother said. "I've got Catholic friends as well, but I could never say that to my neighbors. When things get this tense, it's a matter of survival. You support your own community and dare not speak out of turn."
Ross said she feared IRA retaliation for this week's Protestant intimidation, and predicted Protestants would be driven out of Ardoyne within five years.
Good riddance, says Boyle, adding that Protestants didn't dare threaten Holy Cross before the IRA cease-fire.
"Now, when a pipe bomb goes off, the Sinn Fein politicians come around afterward and we ask them, 'Where are the IRA? What are they going to do about this?' And they just shrug their shoulders," he said.