For many Israeli soldiers, it is the mundane, day-to-day memories of their time in the military that continue to jolt them in post-army life. Regular house searches, arrest and hours at checkpoints fill their minds when they look back and wince.

When several dozen ex-combatants were asked about a time that most affected them, former First Sergeant Omry Balely remembered weeks of boredom at a roadblock near the parched Palestinian city of Jericho.

“The general feeling was that it was a quiet and very safe area,” he says. “When you’re at a checkpoint, you’re in a daily routine of controlling the lives of other people. Who enters and who doesn’t is in your hands – a 19-year-old kid with power.”

They would get agitated and taunt the Palestinians, denying entry or exit to those who said the “wrong” thing, or cuffing one to a barrier for having incorrect documentation. Looking for amusement, his unit handwrote bogus VIP permits for the Palestinians who crossed regularly. They were legally meaningless but added some fun to the long hours in the sun.

Once, an older man in his 50s arrived. He had one of these paper VIP permits, but that day, he came with a donkey. “Where was the donkey’s VIP pass? the soldiers demanded.

Omry Balely. Photograph: Quique Kierszenbaum

“We all laughed at the situation, including the Palestinian,” says Balely, now 30. “But looking back a few years later, I realise what being drunk with power combined with boredom can do to you. You toy with the life and livelihood of a person for entertainment.”

Testimonies like these from 52 Israel Defense Forces veterans are being displayed this month at a gallery in Tel Aviv alongside their portraits for an exhibition called EXPOSE[D]. For a decade, Quique Kierszenbaum, a Uruguayan-Israeli news photographer and journalist, has been documenting those who agreed to speak out about the abuses they saw and often perpetrated. He did this with the help of Breaking the Silence, a not-for-profit organisation founded in 2004 that has been collecting personal military stories, hoping it will show the public the reality of everyday life for Palestinians.

The whistleblower organisation, widely derided in Israel, says abuse is systematic and institutionalised – an unavoidable part of five decades of occupation – rather than the rare the rare anomalies that such incidents are often explained away as. To date, Breaking the Silence has meticulously collected testimonies from more than 1,200 soldiers, although the vast majority do not have their identities revealed. This has led to the army and others questioning the accuracy of their accounts.

At the exhibition, almost half of the portraits are of testifiers who are showing their names and faces for the first time. Photos are hung at eye level in one large room, so viewers have the arresting sense that they are being looked at by all 52. During the decade-long shoot, Kierszenbaum always used the same black background, carrying a pull-out poster with him. All he asked was that the soldiers look at the camera.

“This is part of the message,” says Kierszenbaum, who works freelance for multiple international media outlets, including the Guardian. “These guys were sent on a mission to operate the occupation. They want you to look at them in the eyes and listen to what they have to say.

“The atmosphere in Israel is changing a lot. People who oppose the occupation, people who criticise what the Israeli army is doing, they are called traitors and spies. Because there is no face to them, it’s easy not to confront them. But when people see the pictures around the wall, they will see this is more or less Israeli society. This is your son, your brother, your neighbour.”

It is hard to overstate how vilified Breaking the Silence is in a country where the military is such a revered institution. At one point, an Israeli rightwing activist group infiltrated it, secretly video taping the offices for more than a year. Others pretended to be repentant soldiers themselves to provide false testimony and prove the organisation publishes lies. But it never worked.

The group has faced threats, an attempted arson attack on their offices and a law that was dubbed the “Breaking the Silence bill” to ban them from speaking in schools. Prime minister Benjamin Netanyahu once cancelled a meeting with the German foreign minister after the latter said he would talk to the former soldiers.

Breaking the Silence itself started with a photo exhibition, in 2004, when it was still a rough assortment of recently discharged soldiers who fought in the occupied West Bank flashpoint city of Hebron. They were shocked by the discrepancy between how the occupation was perceived by society and the truth known by many soldiers. So they published photos of their time in uniform and talked about their experiences.

Whistle blower … Yehuda Shaul. Photograph: Quique Kierszenbaum

Yehuda Shaul, an ex-combat soldier, was one of the group’s founders and still runs it. His portrait forms part of the exhibition, one of the first people Kierszenbaum photographed. The accompanying text is a story he has shared for more than a decade, from his time in the early 2000s during the street fighting of the second intifada.

“I would shoot directly at Palestinian neighbourhoods using a grenade launcher in response to Palestinian fire towards the [Jewish] settlements in the city,” the text reads. “It’s clear to me that many civilians were hurt by this fire. We did it without any identification of the sources of shooting from the Palestinian side.” A decision was later made to carry out what he calls “deterrent firing”, shooting every day before the Palestinian militants had even started attacking.

When Shaul first went public with this story, the army said soldiers were educated to behave “according to moral standards in complex situations that include very difficult moral dilemmas”. It said it would investigate all allegations of crimes and interrogated Shaul. However, none of the group’s testifiers has been tried, Shaul says, something he attributes to the fact that he and many others were taking orders from senior commanders who would then be exposed to legal action.

In his testimony, he says he had a responsibility to tell his story. “For years, our society has been making decisions based on incorrect information with no understanding of the meaning of what’s happening on the ground, and from my perspective, this is the vacuum that Breaking the Silence fills.”