When the people of Aleppo, Syria, turned on their taps in early March, they saw clean, running water for the first time in months.

In January, the Islamic State seized the sole water plant that serves the city of Aleppo and shut it down, depriving three million people of drinking water. Syrian forces reclaimed the facility last month.

As the violence in Syria drags into its sixth year, water has become a weapon of war. All sides in the conflict have fought over, or destroyed, water resources to further their military goals.

The United Nations formally recognized access to clean drinking water as a human right in 2010. For much longer than that, international law has decreed that denying civilians access to the basic necessities of life is a war crime.

Yet according to experts we spoke with, there is still too little global awareness and action to protect vital water resources in war zones.

The crisis in Syria is far from the only conflict in the world where water is a battlefield chess piece.

In Somalia, the Islamic militia al-Shaabab has used different tactics to deny water to cities in retaliation against government forces. The Nigerian army has accused terrorist group Boko Haram of poisoning wells and streams before retreating from villages they had captured.

Water infrastructure in Afghanistan was severely damaged by decades of conflict, according to Romila Verma, a University of Toronto hydrologist. Now, projects to repair water and sanitation systems have become a political football between India and Pakistan; each jostles to gain influence in Afghanistan at the expense of the other, Verma tells us.

Verma is involved in the Trans Africa Pipeline project, an ambitious plan to bring water to 11 sub-Saharan countries via an 8,000-kilometre conduit. But violence in countries such as Mali and Nigeria has made it dangerous to construct the pipeline and train locals to maintain it.

While targeting necessities like water is a tactic as old as war itself, what's different today is climate change makes the consequences far worse, says Peter Stoett, an expert in international law and environmental politics at Montreal's Concordia University. Verma agrees: "Sources of fresh water around the world are shrinking. When you make water a pawn, this crisis increases tenfold."

Another difference is that, where once the denial of water served to force the surrender of armies, now it is increasingly a measure to control or punish civilians, says Verma.

What's more, the disruption of sanitation systems can also harm innocent people in conflicts, Stoett notes. In March, an Israeli environmental group warned the destruction of sewage systems in the Gaza Strip could result in a cholera or typhoid outbreak that would have the potential to contaminate cross-border waterways, affecting the countries beyond Gaza, like Israel and Egypt.

One of the first steps in better protecting water resources in conflict zones is raising global awareness of the issue, say Verma and Stoett. "No one it talking about this," Verma says.

Government diplomacy and public pressure can encourage institutions like the International Criminal Court to tackle robbing people of the right to water as they would any other human rights violation in war. Policy makers and military planners must consider how their operations can avoid damaging water resources.

At the UN in 2005, all countries committed to the Responsibility to Protect protocol--to defend human rights in times of war. The world needs to remember water is one of those rights we are sworn to protect.

Craig and Marc Kielburger founded Free The Children, Me to We and We Day. Visit we.org for more information.