Manchester attack: Show of force from police would play into terrorists' hands
Many of those who died in the bombing at Manchester Arena were children. Their tragic deaths may leave us feeling as if Isis is sinking to a new low in its barbaric war, but it's worth remembering that these extremists have executed children in the Middle East.
Terrorists do not discriminate by age. What attracts them most of all is the prospect of causing mass devastation very quickly. It could be on a bus, a train, at a local community centre or football ground.
Any gathering where there are crowds of people has a greater risk of being targeted, as I and my fellow officers knew when we worked to ensure our stadiums were safe during the London Olympics.
Parents will be worrying about their own children after this attack, perhaps thinking twice about sending them to a concert in the future.
Some will be hoping to see a show of force from the security services in order to put their fears to rest, but that would be playing into the terrorists' hands.
Imagine if the police erected a "ring of steel" around arenas, with outer perimeters and cordons being put up to bolster security. Where would you stop? That sort of response would leave the terrorists feeling vindicated.
Anyway, you'll never prevent a determined loner from using themselves or technology to slip a homemade device into the venue unless you put in blast resistant doors and physically strip-search everyone.
Authorities have not rushed to conclude whether this was a direct attack on children because it would quadruple the fear and panic across Britain's school campuses.
Parents might then think schools should be tightening up their security, but even that doesn't guarantee the children's safety. Most universities in America have a campus police force, yet people still get through.
Predicting the unpredictable is not possible. What the police have to do is plan as much as possible, and work with local communities to gather the intelligence necessary to ensure these attacks do not happen. The Northern Ireland Government tried to keep order during the Troubles by introducing internment, which led to hundreds of people being imprisoned without trial due to suspicion of being republican militants.
That policy, a senior IRA man told me, was one of their biggest recruiting opportunities. It's a difficult time to be a chief constable. Every morning that you wake up and nothing has happened is a success. Sadly in the modern world, it's not a question of if an attack happens but when.
Security services have stopped and prevented many attacks, on many occasions foiling the more organised plots thanks to good intelligence. The challenge for police in Manchester is similar in scale. There are so many events for them to watch over, and these terrorists are not necessarily people on MI5 or MI6's radar. They neither have the time, nor authority to watch over them all.
Hugh Orde is a former Chief Constable of the PSNI