More than a billion firearms are in circulation worldwide. Many slip from national stockpiles into the black market, arming gangs, militias, and insurgents.

A new generation of “ghost guns”-3D-printed weapons without serial numbers is making the trade harder to trace, especially in Latin America and parts of Europe.

 Long after ceasefires are signed, the guns remain.

At a tense UN Security Council debate this week, officials warned that the unchecked spread of small arms is fuelling violence from Port-au-Prince to Darfur.

Adedeji Ebo, the UN’s deputy disarmament chief, said small arms account for nearly a third of civilian deaths in some conflict zones.

INTERPOL officials described the problem as “a borderless chain of violence” that police alone cannot stop.

In Haiti, up to half a million firearms are believed to be in circulation, most smuggled and unregistered.

Armed groups now control key highways and ports. Across Africa, the picture is similarly grim.

The African Union’s Mohamed Ibn Chambas called the proliferation of light weapons “a cancer eating away at stability.”

Stockpile management and disarmament campaigns have destroyed thousands of weapons, but the flow continues.

“The guns produced today,” M Ebo warned, “will fuel tomorrow’s wars.” Few at the Council disagreed.