Where were you on the morning of July 7, 2005? You can almost certainly remember.

The four bombs that went off on public transport that day – three on the London Underground, one on a bus in Tavistock Square – not only left 52 innocent people dead but also sounded an alarm call to us all that Islamist terrorism was a real and present danger to our country.

I was presenting my LBC radio show as news filtered through that what we had been told was a “power surge” on railway lines near Edgware Road was nothing of the sort.

I don’t remember much of the three hours that followed. You operate on ­autopilot in such ­circumstances, I ­discovered. But I will never forget the first caller describing motorway gantries on the outskirts of the city displaying the message: “LONDON IS CLOSED. TURN ON YOUR RADIO.”

Tuesday will be the 10th anniversary of the attacks and to mark the ­occasion we’ll play an interview I ­recorded with three men who arguably had more influence over our response to it than any others – Ken Livingstone, then London mayor, Ian Blair, who was head of the Metropolitan Police, and Underground chief Mike Brown.

The day before they came in, by cruel coincidence, we’d been responding to the recent attack in Tunisia by asking what terrorists such as the gunman who killed 38 tourists, were hoping to achieve.

Destruction

We didn’t, I’m afraid, come up with much of an answer.

Then, listening to Ken, Ian and Mike recall their priorities on that fateful day and afterwards, the penny dropped.

Terrorists, like the Tunisian Seifeddine Rezgui and the four Britons who blew up 52 of their countrymen on July 7, want to sow division at least as much as they do ­destruction. They want us to turn on each other, to be suspicious of our neighbours, to consider all “Muslims” to be the enemy of all ­“non-Muslims”.

When, Ken explained, he spoke briefly and poignantly from Singapore, where he’d been celebrating the UK’s successful bid for the 2012 Olympics the previous night, he wanted to stress the importance of getting the city back to normal as quickly as possible.

When, Mike explained, he enquired about keeping the Underground network closed for a few days while risks were ­assessed he was relieved to be told to get the trains running again as quickly as ­possible. Some were back in service the following morning.

Keep Calm and Carry On has ­become a popular poster slogan in recent years.

When you mark the anniversary on Tuesday remember that it’s also the best possible response to the murderous savages who ­continue to threaten us.