In 1994, on the eve of Rwanda’s genocide, Radio Mille Collines, in Kigali, incited listeners with a venomous message: “To kill the big rats, you have to kill the little rats.” It was a veiled command to murder the youngest generation of Tutsis, the country’s minority tribe. In less than four months, an estimated three hundred thousand children were slashed, hacked, gunned, or burned to death, according to the United Nations. Among the dead were newborns.

The Rwandan slaughter was not unique. The specific targeting of children is one of the grimmest new developments in the way conflicts have been waged over the past fifty years. In the eighteenth, nineteenth, and early twentieth centuries, roughly half of all deaths in conflict zones were civilian, according to the U.N. During the Second World War, civilians accounted for two-thirds of the fatalities. By the twentieth century’s end, almost ninety per cent were civilian.

Children have accounted for increasingly large chunks of those deaths. In 1995, UNICEF reported that roughly two million kids had been killed in wars over the previous decade—more children than soldiers. “Children are not just getting caught in the crossfire, they are also likely to be specific targets,” Graça Machel, the Secretary-General’s Special Representative, declared in the first U.N. “Children in War” report, in 1996. She went on:

When ethnic loyalties prevail, a perilous logic clicks in. The escalation from ethnic superiority to ethnic cleansing to genocide, as we have seen, can become an irresistible process. Killing adults is then not enough; future generations of the enemy—their children—must also be eliminated.

In the twenty-first century, the escalating dangers to children in conflict zones are often overlooked amid the terrible dramas of individual loss, such as the recent killing of three Israeli teen-agers and a young Palestinian. But the worldwide numbers are unprecedented. “We’re seeing everywhere that violence against children is an epidemic, amplified in conflict situations,” Susan Bissell, UNICEF’s chief of child protection, told me this week. “One billion children are today living in countries and territories affected by war or conflict—and it’s fair to conclude that large numbers suffer violent injuries and death.”

According to the Secretary-General’s latest “Children and Armed Conflict” report, issued on Tuesday, one of the most dangerous places to be a child is Syria. To take a single example: in the spring of 2011, Hamza al-Khateeb, a pudgy thirteen-year-old, got separated from his parents during a protest against the government of Bashar al-Assad. His mutilated corpse—with gunshot wounds, cigarette burns, a shattered jaw and kneecaps, and a severed penis—was returned to the family a month later. A government medical examiner reportedly claimed that the boy had been shot during the protest, and that the disfigurement was either normal decay or faked. Pictures of the body circulated on the Internet and in Syrian media, perhaps as a warning to dissidents and parents.

Since then, at least eleven thousand Syrian children—and probably thousands more—are estimated to have died in the vicious civil war. Almost eight hundred were summarily executed, with dozens killed by chemical weapons, according to the Oxford Research Group. One of the most memorable pictures from the Syrian regime’s use of sarin nerve gas last August was the long row of little corpses, wrapped in white shrouds that exposed innocent faces, as they awaited burial.

Other kids have become collateral for combatants. As Israel searched for the three abducted teenagers, UNICEF issued a statement of “grave concern” about the May 29th kidnapping of a hundred and forty Kurdish schoolboys in northern Syria. As they were returning to their hometown from junior-high-school exams in Aleppo, they were seized and taken hostage by the Islamic State of Iraq and al-Sham (ISIS). Four managed to escape; the rest are still missing.

Technology, ranging from nuclear weapons to small cluster bombs, has made non-combatants, especially the young, particularly vulnerable. I lived in Lebanon during its civil war. After the Israeli invasion in the nineteen-eighties, dozens of Lebanese kids were killed by cluster bombs, either in direct hits or by stepping on them or after mistaking them for toys.

When it comes to the use of insidious weaponry, nearly all sides have something to answer for. In Afghanistan, at least thirty-five thousand children have been victims of land mines since 1979, according to the U.N. Special Representative for Children and Armed Conflict. When I visited the orphanage in Kabul in 1999, during the Taliban’s rule, a turbaned official lamented losing orphans who wandered into neighborhoods where land mines or explosives had been deposited by assorted domestic and foreign militaries over the previous two decades. Fifteen years later, Afghan children are still dying from the weaponry of conflicts both old and new.

Death tolls for kids are sometimes fuzzy and often not final, even long after wars end. In Bosnia, more than a thousand children are reportedly missing from a war that ended a generation ago. Aid groups also point out that politicians, militias, and interest groups exploit child deaths—both their numbers and circumstances—for propaganda value, a recurrent controversy in counting the death toll in Iraq’s various conflicts.

Regardless of public revulsion, U.N. officials told me this week, the rising number of child casualties is unlikely to subside anytime soon. Today’s wars are increasingly within countries rather than between them; the fighting has moved to city streets, invading the playrooms of homes and kindergartens.

Photograph by Moises Saman/Magnum.