After the Japanese invasion of Java in 1942 and KNIL's capitulation, his father was sent to a POW camp near Tokyo, Japan. Jeroen, his grandmother (Elisabeth Henrica), his mother and his sister were sent to the Japanese detainment camp 'Kramat'. After some months they were transferred to the Tjideng camp, in a Batavia suburb. His grandparents did not survive these camps. In 1986 Jeroen wrote the autobiographical novel "Bezonken Rood" (translated in 1988 as "Sunken Red"), about the lifelong effects of this Japanese internment.