Twelve-year-old Nesma al Haddad spent the summer in the safest part of her apartment building: the living area on the ground floor of a 12-story building. The main entrance was just a few steps away, and there were few windows. Her room upstairs, with her bed and her assortment of beautiful collectibles, went unoccupied.

With Israel and Hamas at war in Gaza, Nesma tried to carry on with her normal life, hiding her anxiety from her five siblings, despite the sounds of explosions and gunfire during the bombardment of the surrounding neighborhood.

More than once, Nesma and her family were forced to flee to a neighbor’s house; an apartment on the eighth floor was a target. She would leave behind her belongings, except for a suitcase, packed in advance with her favorite clothes and a toy.

“I did not fear anything,” Nesma says. “I worried about losing my favorite toy that I had bought during the last war, in 2012. But I was more worried about losing one of my family members.”

Hers is an all too common story in Gaza these days, and it reveals the invisible scars borne by so many children of war. When talking with these children, and hearing their experiences, one learns how deeply they have been affected by the violence around them — trauma that will take years to heal fully.

Psychologist Jasser Salah met with Nesma during the war several times to assess the impact of the war on children. “Those remarks are her attempt to deny her feelings of fear and anxiety,” he says, adding that Nesma feels great pressure to remain calm for her family’s sake.

Such pressure, Mr. Salah adds, poses a greater challenge to the Gaza Strip’s children than its adults. At their early stage of psychological development, the stress of enduring armed conflict can leave deep and lasting impressions.

Gaza’s young may be especially vulnerable. A report published in 2012 by the United Nations notes the Gaza Strip has “one of the youngest populations worldwide,” with about 51 percent of the population under 18 years of age.That same report predicted the Gaza Strip could become virtually unlivable by 2020, according to available trend data for access to food, drinking water, electricity, sanitation infrastructure, health care and schooling. A shortage of clean water alone could create a crisis as early as 2016, due to the accelerating depletion of groundwater wells and inadequate sewage systems.

Additionally, the Palestinian Ministry of Education lists hundreds of schools as damaged, and dozens destroyed entirely. The scope of the devastation is vast.

“The needs are much greater than what we can provide,” says Sami El-Yousef, CNEWA’s regional director for Palestine and Israel, who has been working with numerous Catholic aid agencies operating in the region to coordinate aid, ensuring that scarce resources are not lost to duplication and competition.

Though emergency relief efforts are still underway, making a prosperous future a possibility for Gaza’s youth will require development initiatives for years to come — possibly, even, for decades.

“Gaza,” explains Mr. El-Yousef, “has to remain a priority for the foreseeable future.”

Over the past seven years, Gazans have endured three wars and an ongoing blockade by Egypt and Israel, initiated in 2007. Together, these conditions have pushed Gaza’s unemployment and poverty rates to about 40 percent each.

Wissam Abu Shaqfa, 10, was too young in 2008 to remember the Israeli military incursion called “Operation Cast Lead.” However, he remembers clearly the fighting in 2012, which continued for eight days. He says the recent 50-day war was the worst of the two.

“In the first days, I used to move in the city normally,” he says. “But as it got worse, dad forced us to stay indoors. We sometimes still went outside — I used to accompany him to his grocery store, two streets away from our home.”

Psychologist Jasser Salah explains that Wissam has been suffering through a severe shock after the death of his close friend — a beloved uncle who never had children of his own and had treated Wissam as a son. The boy has since isolated himself, preferring to remain alone.

“Wissam returned to school after the war ended, adds Mr. Salah, but he felt detached.” The psychologist says it could take Wissam a long time to make new friends and cope with his loss.

It is a loss many children his age in Gaza are experiencing. And it is taking a toll. According to UNICEF, more than 500 Palestinian children in the Gaza Strip were killed during “Operation Protective Edge” this summer, and more than 3,300 children were injured. Even among those who suffered no injuries, many have experienced significant psychological trauma.

“When I’m speaking to children today, I’m finding that they are withdrawing from normal interactions with their families, they’re having nightmares, they’re bed-wetting, they won’t let their parents out of sight,” says Pernille Ironside, chief of the UNICEF Gaza field office. “They’re truly in a state of trauma.”

It is part of what she calls the “destabilizing impact” of feeling that no safe place exists in Gaza.

“Children need to have that sense of security,” she says.

Yet for many, such security was damaged during the unpredictable bombings. Their lives and sense of well-being, like the landscape around them, were shattered.

When 14-year-old Tamer al Nakhala and his mother took a taxi to visit his grandmother, a bomb exploded just yards from the car. Though shaken by the event, they arrived safely.

However, when the time came to leave, the two could not find a cab to take them home before the next round of heavy shelling. In the darkness, the boy ran with his mother all the way home, surrounded by the sounds of a mounting barrage of artillery.

Since that night, Tamer’s family has observed differences in the boy’s behavior. Among other changes, he now suffers from insomnia. He rarely seems to have any appetite. He has also developed a fear of the dark.

“Since then, Tamer turned into someone else,” says Ahlam, Tamer’s mother. “Despite being the eldest among his brothers, he behaves as children do. He refuses to sleep at night, often waking up his siblings for company.

“He sleeps intermittently during the day time,” she adds.

“I was afraid of death,” admits Tamer, a shy boy who used to spend his time playing computer games.

“I’m always afraid of losing my little brother, who is the closest one to me.”

The common denominator between Nesma, Tamer and Wissam is not only the psychological impact of war, but also a deep-seated need to hide their true feelings.

At her home in Al Daraj neighborhood in eastern Gaza City, Ahlam al Nakhala tells Tamer: “You are a grownup, and should not fear. Look at your siblings, they do not fear.

“You should sleep and eat,” she says, concerned for her son’s growth.

But Mr. Salah says this attitude is commonplace.

“Parents in Gaza are rooted to their inherited culture that considers fear a weakness.” This, he says, can exacerbate the problem.

“Raising the parents’ awareness is essential to help children to overcome their psychological trauma,” he says. “This is the reason behind conducting field visits and meetings with parents.”

Nesma’s father, Nabil al Haddad, has been consulting psychiatrists about how to help his daughter process the recent events.

“My wife and I tried hard to help her,” he says. Their first instinct was to shower Nesma with gifts and attention, but it soon became clear that the family needed to seek professional help.

“We hide our own feelings of fear and anxiety from her,” Mr. al Haddad says, “but it was so hard to stop her from being scared, even when we would all sleep in one room.”

To this day, Mr. al Haddad says, Nesma is easily startled by loud noises — even the sound of speeding cars. She has not slept in her own bed since returning to find the windows of her room shattered from nearby shelling.

According to a UNICEF report, about 373,000 Palestinian children in the Gaza Strip — or 35 percent of the children there — require psychological intervention after the summer’s war.

“This is an area where the need is great,” says Sami El-Yousef. “Countless men, women and children will be suffering the after-effects of this conflict for a long time to come.

“Some wounds are invisible and deep,” he adds.

Psychological assistance is a key component of the programs supported by CNEWA through Gaza’s Christian institutions, including the YMCA of Gaza, the Myrrh Bearers Society of the Orthodox parish of St. Porphyrios, the Anglican-run Al Ahli Arab Hospital and the various initiatives of the Latin Patriarchate.

The results so far show promise.

At one of the institutions CNEWA supports, the Rosary Sisters School, the scene looks markedly different than other places. The students are playing, drawing and dancing, expressing and discussing their summer.

Sister Nabila Saleh, the school’s principal, noticed a difference in the students’ behavior when they returned to school. The children were tense, and became more violent with one another on the playground.

“It was obvious the war had a bad impact on the children, and for that reason we decided to dedicate the first week to stress release by playing, drawing, dancing and writing — in cooperation with specialists,” Sister Nabila says.

“Most of the children responded positively during the social activities. Some students profoundly need additional treatment — especially those who lost loved ones, or those whose homes were completely demolished.”

Hassan Zeyada, director of the Gaza Community Center, which offers psychological support for children and their parents, says the continuation of the current crisis and the recurrence of the military conflicts in the Gaza Strip complicate the situation. It serves, he says, to increase the level of violence in society every day — which makes any recovery an uphill struggle.

“In light of the bitter economic and political realities in the Gaza Strip,” he says, “it is hard to achieve our goals. The aftermath of the war will affect [the children’s] behavior for a long time.”

In particular, Mr. Zeyada expresses concern that constant exposure to violence will lead children to feel it is normal.

Ten-year-old Wissam seems to illustrate those worries, especially when someone asks him what he wants to be when he grows up.

“I’m not going to be an engineer or inventor, because I won’t find a job,” Wissam says. “If I become a fighter, I’ll find work to do.”

CNEWA’s Sami El-Yousef says attitudes such as Wissam’s are, sadly, all too common — and need to be addressed.

“We cannot allow that to happen,” he explains. “The best way to change this is to ensure there is a political solution leading to an independent and viable Palestinian state.”

Meanwhile, 12-year-old Nesma, offers another glimpse of Gaza’s future — and her own.

“When I grow up I won’t buy toys, even during wars,” she says.

“I want to live in another place in the world rather than here.”

Tamer, when asked about his future, gives the question long and careful consideration.

“When I grow up,” he says, “I want to become rich, to buy a big house that rockets and missiles won’t penetrate.”

Hazem Balousha is a journalist based in Palestine.