Increased security needed after Barcelona attack
The horrifying events in Spain once again underlines the vulnerability of European cities and the lengths violent fanatics will go to in order to attack and disrupt our way of life.
Terrorists, apparently inspired by Islamic State, have again shown they do not need sophisticated weapons to cause carnage, using a hired van to inflict maximum damage on innocent people enjoying the sights of Barcelona.
However, there was clearly a degree of planning and co-ordination in this week's murderous attacks.
Hours after a militant drove a van through the famous Las Ramblas area, killing 13 people and injuring more than 100, police shot dead five men in a car which rammed into civilians - killing one woman - in the town of Cambrils, 68 miles from Barcelona.
The attacks are being linked to a explosion at a house of Wednesday which police believe was part of a plan to cause death and destruction on an even greater scale.
The difficulty for governments and security services in European countries is finding a way to stop these terror attacks.
They know they are dealing with extremists who are prepared to die for their beliefs and determined to kill as many people as possible.
The attacks are absolutely indiscriminate. Those killed or injured in Barcelona came from 34 countries but the jihadists do not care where their victims come from or what religion they are - they are all the enemy in their eyes.
Places popular with tourists have also been targeted, as we have seen in Nice, London and elsewhere.
The terror groups want to create fear and chaos, making people afraid to travel or visit places where there are crowds.
And there is no doubt that these attacks do cause alarm and apprehension.
A number of Irish people were caught up in Thursday's terror and Spain is a major holiday destination for tens of thousands of people, north and south.
This brings the awful events of this week very close to home and people across Ireland will wish to show support for the people of Spain at this time.
But the frequency of this type of attack means that the authorities need to look at ways to combat the threat and safeguard citizens.
This could mean tighter controls on the hiring of large vehicles and the bolstering of protective measures in areas usually thronged with tourists.
As we have seen following other atrocities, people are determined to get on with their lives and not allow the terrorists to win.
However, given recent attacks, people also have to be prepared to deal with increased security.