People are outraged – and rightly so. In just 24 hours, nearly one million people have signed a petition honoring the memory of the 132 children killed by militant extremists in Peshawar. Their call for every child in the world to be able to attend school safely has already been heard by political leaders in Pakistan and far beyond.

Among the signatories to the petition, organized by the groups A World at School and Avaaz, are children’s rights activists, such as Malala Yousafzai, winner of the Nobel Peace Prize, and political leaders, including the entire cabinet of the Democratic Republic of Congo.

The violence in Pakistan is the latest example of what is becoming a horrific pattern: armed men using schoolchildren as pawns in their conflicts, turning access to education into a weapon of war. On December 17, just one day after the Peshawar massacre, yet another 100 children were kidnapped in Nigeria – allegedly by gunmen from Boko Haram, a terrorist group whose very name means "Western education is forbidden.” The latest assault took place only 30 miles from the village of Chibok, where the Islamist militants shocked the world by abducting more than 200 Nigerian girls in April.

Schools – which should be safe havens – have instead become targets for terrorist groups hoping that their horrific massacres will be reported around the world. In the past five years, there have been more than 10,000 attacks on schools and schoolchildren. On the same day that Islamist militants were shooting schoolboys in Pakistan, terrorists murdered 15 Yemeni children on a school bus. In Afghanistan, Colombia, Pakistan, Somalia, Sudan, and Syria, at least 1,000 schools and colleges have been bombed or raided. In the aftermath of the attacks, the schools are usually closed, with the students left to roam the streets.

For many survivors, the chance of an education is lost forever. Evidence shows that if a child is out of school for a year or more, there is a 50% chance that he or she will never return.

The inspiration for the appeal for safe schools came from events in Nigeria, where Boko Haram has killed 171 teachers and hundreds of students in the past two years. Originally the brainchild of A World at School, the concept has been taken up by the Nigerian government. President Goodluck Jonathan and the country’s finance minister, Ngozi Okonjo-Iweala, championed the idea after learning that the abductions by Boko Haram had caused girls to become afraid to go to school.

With the support of the international community, the government introduced the Nigerian Safe Schools Initiative, a 500-school pilot program in the country’s northern states, where the attacks have taken place. The program hires security guards, links schools to police stations by mobile telecommunications, and fortifies school buildings against assaults. It also organizes local security coalitions of teachers, parents, police, community leaders, and students.

To be sure, these measures alone cannot eliminate the possibility that determined terrorists will strike a given school. But the knowledge that attackers will face resistance, and that the police and army will be quickly alerted, provides an important deterrent. It is also vital that parents receive the message that everything possible is being done to make schools safer for their children.

The Nigerian initiative should be expanded as quickly as possible to every country where terrorists are likely to strike. An international fund should be created to support Pakistan’s government as it works to ensure that its schools are protected. Globally, what is needed is tough, uncompromising security measures and a clear declaration that schools will be treated – like hospitals – as protected zones, off-limits to attackers. The killing of schoolchildren must be punished as a crime against humanity.

The world cannot afford to stand by as schools are shut down and children become afraid to pursue an education. As stated in the petition that so many have signed, "All children deserve the opportunity to learn and achieve their potential.” It is time we made that a reality.

Gordon Brown, former Prime Minister and Chancellor of the Exchequer of the United Kingdom, is United Nations Special Envoy for Global Education.

Copyright: Project Syndicate.