MARIB, Yemen — A display on one side of the doorway holds children’s drawings of violence and gore: red scribbles of blood on pencil sketches of bombs, bullets and bodies; a machine gun firing across a stone wall into a tent; a detailed depiction in crayon of a Kalashnikov rifle.

A display on the other side holds happy visions of the future — like a boy with his foot on a soccer ball holding up a trophy, and a smiling army officer with three big stars on each shoulder.

In between is the entrance to the center for the rehabilitation of child soldiers in Marib, Yemen, financed by Saudi Arabia. A photograph of King Salman hangs on the wall.

Open a little more than a year, the center has provided up to six weeks of schooling and play in a comfortable villa for more than 200 boys enlisted by armed groups fighting in Yemen.