Should you even try? Or is it best to overlook the children's past and let them get on with their new lives?
Hundreds of teachers face this dilemma as the bombing started in Afghanistan this week.
But in Villiers high school, Southall, London, school counsellor Chantal Waldron offers children the chance to share their feelings about their past - and their future.
Ms Waldron said: "It is absolutely vital children have a chance to talk about it, if they want to. In my experience, they've never not wanted to talk. They may be reluctant to begin with, they don't know how to begin and releasing such strong emotions can be frightening. But I tell them it is OK to have a cry and we talk about it one step at a time."
Ms Waldron is a retired teacher and trained counsellor. Her reputation as a listener means staff and children alike will alert her to pupils they are worried about.
These may include the school's refugee pupils, about 40 in a population of 1,200. They have fled from conflicts around the world, including Somalia, Sri Lanka and Kosovo, as well as Afghanistan.
Ms Waldron, who took early retirement as head of Year 9 last year, said:
"It helps them because they feel nobody knows about what they've been through, they feel very isolated. They need to have somebody to tell them and reassure them that they are safe."
English as an Additional Language at www.tes.co.uk