A relative of a Sri Lankan victim of an explosion...

A relative of a Sri Lankan victim of an explosion at a church weeps outside a hospital in eastern Batticaloa on Sunday. Credit: AFP/Getty Images/LAKRUWAN WANNIARACHCHI

Among those killed in the tragic and ruthless bombings of churches and hotels on Easter in Sri Lanka is a young boy who had a lifetime ahead of him.

Kieran Shafritz de Zoysa was a fifth-grade student at Washington’s Sidwell Friends School. He had taken a leave of absence to study in Sri Lanka and planned to return to the private school this fall. His was among the more than 350 lives lost — at least four Americans among them — in the attacks.

We often think that international conflicts are not our business. Or we pretend that we have finished our work in Syria or Iraq or Afghanistan and should bring U.S. troops home. But in a second, we are reminded that nations are linked and that terrorism has no single home.

We can’t retreat from the world, given the extremist ideologies and actors around the globe. Americans live, work and study overseas and we have the moral, financial, military and technical power to build a stronger and safer environment for them and for everyone who shares the world with us.

President Donald Trump has told Americans that the Islamic State is done and that the threat has been eliminated. If, as suspected, the terrorists in Sri Lanka are part of an extremist group that has hijacked Islam and plotted to undermine a country to resurrect its caliphate or remind us that ISIS is not finished, we should question our administration about its policies and premises. We have a right to know more about what our government is doing and how we are countering violent extremism around the world — even in places like Sri Lanka, which was emerging from a civil war and did not heed warnings about terrorist plots. Conflicts like civil wars are messy and resolving them takes time, patience, resources and political will.

Maybe some nations are not doing enough in terms of sharing intelligence and public diplomacy to counter violent extremist narratives online. Often nations are lulled into a false sense of security in the absence of terrorism. Governments must fight terror in a global age in which money, weapons and radical ideas move quickly.

It is easy to hunker down behind walls and fortresses and pretend nothing can affect the United States. But those walls didn’t protect Kieran and the other terror victims.

Not every fight is America’s fight. But choosing which threats to confront — when and where — is what we rely on our elected officials to do. The United States should not be a mere observer. Our children deserve better.

Tara D. Sonenshine is a former U.S. undersecretary of state for public diplomacy. She advises students at The George Washington University Elliott School of International Affairs.