As a typical mother, news of an upcoming school trip to soak up the archaeological delights of The Petrie and British museums in central London for my nine-year old elicited excitement plus the usual set of concerns. Will two chocolate biscuits in his packed lunch be enough? Will he be too warm in his coat or too cold without it? Can I really trust him to take and bring home his school cap?

Then an email arrived from their Jewish school less than 24 hours before the trip that swept all my benign concerns to one side and forced me to embrace an even bigger worry. Some parents, the school explained, had expressed reservations about the children travelling on the Tube and preferred, for reasons of security, that the school book a private coach to take them into and out of town. The date of the school trip was just five days after the terrorist attacks in Paris.

I sat at my desk, cogitating over the contents of this communication from the school and wondering how to respond. Electing to put the children on the coach was not my gut instinct. The Tube is a quicker and far more interesting way to travel. But was I being too blasé about the threat to public transport post-Paris?

With the horrors of the recent stabbings in Israel all over social media and newspapers and TV coverage at saturation point since that fateful Friday evening in Paris, had I somehow become desensitised to the likelihood of attack?

In the end, the children went by coach and had a fabulous day, despite spending a little too much time stuck in rush-hour traffic and not enough poring over Egyptian mummies.

All of our children have to wear a high-vis jacket

But, when the trip was over, the questions and the rumbling uncertainty that followed it remained. How vigilant do Jewish schools really need to be? Not only has our school increased its quota of security guards this year but new funding has created a pedestrian and vehicle security lock-in zone with high prison-style railings and staggered entry points that could even test James Bond.

As for trips, our school, like many Jewish schools, operates strict guidelines and has done for a long time.

As well as being accompanied by a dedicated security guard, all the children wear a high visibility jacket without the school name or logo, boys are expected to wear a cap instead of a kippah and their tzitzit -part of the everyday school uniform - must be tucked in. I call it camouflage; others call it blending in.

This vigilance by the school when it comes to protecting our children is impressive and designed to reassure. But, in the light of Paris and the current severe national threat level, is this no longer enough?

Are we now meant to chaperone our children in and out of our security-gated school premises on private coaches for fear a trip on public transport could expose them to too much risk? It is a worry that even the schools themselves aren't sure about, the coach in our case is only laid on at the insistence of parents, not of the school.

''After incidents like Paris it is only natural that parents will worry that it might mark the beginning of a new terrorist campaign or encourage a copycat incident in this country and be fearful of sending their children on public transport,'' says Mark Gardner, Director of Communications at Community Security Trust (CST). ''On the Saturday night after the Paris attacks, we sent a security advisory notice to every Jewish school after a discussion with the police and government to explain there was no evidence of a higher threat to Jews at this time, but it is up to each school to make their own risk assessment. Would CST have complained if children were going on school trips by tube? No. But it's up to the school to adapt its plans according to the reaction of the parents and going by coach is likely to be more secure than public transport."

So, in terms of security, it seems our school's decision to alter the children's travel plans at the last minute was a reasonable one to make, especially in the light of the three-day lock-down continuing in Brussels as I write, with its metro, shopping centres and public buildings closed.

Still, I can't help but think of all those Parisians sitting in their coffee shops after the attacks, brazenly drinking their café au laits and puffing on their Gauloises, their chins set to stubborn as they talked of defiance and the terrorists' inability to alter their way of life.

To hide and be afraid is to let them win, was their overriding message.

And yet our reaction, albeit based on threats and acts of terror against the Jewish community worldwide that pre-date Paris, seems grounded more in fear.

Perhaps that is simply our inheritance; to kvetch about security for our children on school trips at the same time as deciding how many chocolate biscuits to put in their lunchbox. We get on with our lives but we worry; nothing new there.