How early should something be done?
The appalling crimes of the two small boys in Doncaster lead, inevitably, to the question: "Should something have been done earlier?"
The answer must be yes - but the evidence is that something should have been done much, much earlier. Before the neighbours saw them scavenging for food and clothing. Before they got into trouble with police for violence and burglary. Before they were expelled form their local primary school.
What these children's behaviour tells us is that they lacked empathy. Empathy is the ability to share and understand another person's emotions and feelings - to put oneself in someone else's shoes. Without it, even very young children are capable of horrifying cruelty.
I remember making a film for Newsnight in 1993 after the conviction of two 10-year-olds for the murder of the toddler James Bulger. What I wanted to understand was how such young children could commit such a ghastly crime. My research took me to Edinburgh, I recall, and a research programme looking at the bonding of mothers and babies.
A mother was put into a sealed room with her infant and monitored by cameras. She was instructed to avoid making eye contact with the baby, whatever the child might do.
As we watched through a two-way glass, the baby began quickly to become agitated. Within a few minutes, its apparent desperation to make eye contact with its mother resulted in tears. A few minutes later, the child was almost hysterical - red in the face and screaming. The experiment was stopped.
I was asked to imagine the same situation in a domestic setting - a young mother, perhaps herself a victim of abuse, struggling to bring up a child in a chaotic household. Without help and support, it was suggested, such distress might generate further chaos and itself lead to the abuse of the child.
I then went to a project which supported mothers with "difficult" toddlers. Even by the age of two, these children were clearly emotionally injured - some biting and scratching other kids, others cowering in a corner.
My final stop was an organisation in Oxford which cared for deeply troubled children from the age of about seven. They told me, to my surprise, that in some cases the damage was so bad that the youngsters would never fully recover. Before their eighth birthday, it was already too late to rescue them.
That was 16 years ago. Three years ago, I was invited to interview the then prime minister, Tony Blair at Chequers, in an exclusive for the BBC. He told me of his conviction that one answer to the problem of anti-social behaviour in children was to target vulnerable pregnant women.
He showed me tables and graphs, brain scans of babies and scientific reports. His conclusion was that we could spot children at risk of becoming socially problematic before they were born, and that if we provided the right support, the benefits for those families and wider society would be huge.
Some papers dubbed his idea FASBOs - foetus ASBOs - and ridiculed the notion that government should brand babies as troublemakers even before they had left the womb.
But the idea of very early intervention is no longer quite the stuff of partisan politics.
Former Tory leader Iain Duncan Smith and the Labour MP Graham Allen are both evangelical about it and have together written a pamphlet on the subject [884Kb PDF].
We have seen the introduction of Family Nurse Partnerships in some parts of the country, offering intensive support for vulnerable, first time, young parents.
Family Intervention Projects, piloted in Dundee and the north west of England, have shown encouraging results when "a strong, persistent and assertive key worker" works with chaotic families - offering intensive support but with the threat of sanctions .
From what we know of the Doncaster case, it would appear that the family of the two young boys had been allowed to go from chaos to catastrophe. Yes, something should have been done. But probably it needed to happen before the children were even born.