Maintaining a normal society shows attackers they cannot prevail

This particular attack took the form of a bomb that detonated on a packed Underground train.

There will almost certainly be more such terrorist attacks in the UK’s capital city and elsewhere in Britain.

There will also probably be more terror attacks in mainland Europe and in America.

It is almost as if the populations in all these countries have come to understand that the attacks will continue and that there is only so much that can be done to prevent them.

During the Troubles in Northern Ireland this spirit was already apparent by the mid 1970s, not long after the terrorism peaked in 1972.

Life went on and some element of normality was established to a degree that surprised the relatively small number of visitors who came to Northern Ireland in those years.

That is our best response to the terrorists – to continue in a way that demonstrates that they cannot prevail. It is the one thing that might make them see the futility of their campaign.

Recent European attacks, in places from Manchester to London to Barcelona, have been horrendous and disturbing but they do suggest that Islamic extremists have fewer volunteers than they would like to have.

Many hundreds of Europeans have offered to fight and die in the cause of jihad in places such as Syria, and yet if the terrorists had huge ranks of adherents they would be attacking civilian targets every day and killing thousands of people every week.

Despite all of these indications that the fanatics are not making the progress they might hope to make, it is still grim to think that there is any risk at all to civilians.

The bomb that exploded at Parsons Green was intended to cause mass deaths. We can only be vigilant, live in hope and support those forces who work to keep us safe night and day.