Every day, another once-vibrant Syrian school is bombed or militarised, with two million children now in refugee camps or exiled to makeshift tents or huts.

And next week will mark the first anniversary of the extremist group Boko Haram's night-time abduction of 220 schoolgirls from their dormitories in Chibok, in Nigeria's northern state of Borno. With continued assaults on local schools, Boko Haram has escalated its war against education - making the last two years Nigeria's worst in terms of the violation of children's rights.

In the past five years, there have been nearly 10,000 attacks on schools and educational institutions.

Why is it that schools, which should be recognised as safe havens, have become instruments of war, and schoolchildren have become pawns in extremists' strategies? And why have such attacks been treated so casually - the February abduction in South Sudan elicited barely any international comment - when they in fact constitute crimes against humanity?

In the depraved minds of terrorists, each attack has its own simple logic; the latest shootings, for example, are revenge by al-Shabab for Kenya's intervention in Somalia's civil war.

But all of the recent attacks share a new tactic - to create shock by exceeding what even many of the most hardened terrorists had previously considered beyond the pale. They have become eager to stoke publicity from the public outrage at their methods, even transmitting images of their crimes around the world.

But there is an even more powerful explanation for this spate of attacks on children. A now-common extremist claim is that education is acculturating African and Asian children to Western ways of thinking (Boko Haram in the local Hausa dialect is taken to mean "Western education is a sin"). Moreover, extremists such as Boko Haram and al-Shabab calculate that they can attack schools with impunity.

Hospitals tend to be more secure, because the Geneva Conventions give them special protection as safe havens - a fact often recognised by even the most murderous of terrorist groups.

Until recently, we have done far too little to protect schools and prevent their militarisation during times of conflict. But, just as wars should never be waged by targeting hospitals, so combatants should never violate schools.

Once slow to respond, the world is now acting. Thirty countries have recently signed up to the Lucens guidelines for safe schools, which instruct their military authorities on how to prevent schools from being used as instruments of war.

Leila Zerrougui, special representative of the UN secretary general for children and armed conflict, recommends designating abductions of children from schools a "trigger violation" for the naming of terrorist organisations in the secretary general's annual report to the Security Council.

Thanks to the United Nations Children's Fund, the Global Coalition to Protect Education from Attack, the Global Business Coalition for Education, and former Nigerian finance minister Ngozi Okonjo-Iweala, Nigeria has now piloted the concept of safe schools.

This has meant funding school guards, fortifications and surveillance equipment to reassure parents and pupils that everything possible is being done to ensure their schools are safe to attend.

Now, under Prime Minister Nawaz Sharif, Pakistan is adopting the safe school plan.

In a year when there are more local conflicts than ever - and in which children have become among the first (and forgotten) casualties - it is urgent that we make stopping attacks on schools a high priority.

In dark times, children and parents continue to view their schools as sanctuaries, as places of normality and safety. When law and order break down, people need not only material help - food, shelter, and health care - but also hope. There is no more powerful way to uphold the vision of a future free from conflict than by keeping schools running.