The sickening events in Catalonia in the last few days are the latest iteration of a pattern of low-tech jihadist terrorist activity involving the use of vehicles to kill and maim the maximum number of 'infidels'.
According to international NGO the Counter-Extremism Project (CEP), there have been more than a dozen attacks in the last three years, killing some 200 people and maiming hundreds more.
As Isil's caliphate in Iraq and Syria is progressively reduced territorially and many of its fighters return to their homes in the West, the terrorist organisation has called on its followers to strike at members of the anti-Isil coalition, of which Spain is one, using knives or vehicles.
Spain is also a target because of the presence of a caliphate, Al Andalus, in the country for hundreds of years, coming to an end in 1492. It is said that, in North Africa, some descendants of those finally expelled from Spain still have keys to their ancestral homes and have vowed to return. As recently as 2014, an Isil member told the press: "Spain is the land of our forefathers and, Allah willing, we are going to liberate it."
Much of this may seem to have little relevance to Ireland but the events in Spain are in fact a reminder of how interconnected we have all become. And not always in a positive way. Such was the indiscriminate nature of the attack that the dead and injured in Catalonia came from over 30 countries, with the van driver in Barcelona zig-zagging to mow down as many people as possible.
The arrest by the gardai of an Isil supporter two weeks ago and the fact that one of the London bombers had resided in Ireland for some time highlights the need for cross-border co-operation between British and Irish police and law-enforcement agencies to intensify their joint collaboration. Ireland's land border with the UK - and paradoxically both countries' determination to keep the border as transparent as possible - exposes Ireland to the prospect of jihadist cells planning an attack in the Republic, executing it in the UK and then retreating to the Republic to plan further attacks in the UK or further afield .
No Irish government will wish to tolerate the presence of jihadi cells on its territory when fellow EU states (even soon to be former EU states) are under attack. The UK is home to millions of Irish men and women, any of whom could be unwittingly caught up in one of the indiscriminate attacks such as the UK has witnessed recently in Manchester and London.
What is to be done?
While it is impossible to prevent all car-ramming attacks, some physical measures in the shape of barriers around public places where large numbers of people are likely to congregate, particularly during festivals, rallies and the like, should be actively considered. But the source of the problem is the ability of jihadists to infect the minds of the young - so many of the attackers are young men and boys - through the use of social media.
Isil has repeatedly used such platforms to propagate its poisonous message and through encrypted chats to trigger specific attacks, often amplifying massively the voices of Islamist clerics.
Governments have belatedly become sensitive to the threat and the need to combat it by pressurising the social media outlets to interdict the use of their sites for murderous purposes.
Slow to react, some of the larger players have now responded to governmental and independent pressure from organisations like the CEP to close down jihadist sites, preventing them from the gross misuse of their platforms to recruit new members and reach their target audiences.
Yet the appearance and reappearance of Isil videos on YouTube (owned by Google) calling for vehicular terrorist attacks raises serious questions about the company's avowed commitment to confront terrorist recruitment on its platform.
And other sites like Telegram employ encrypted messaging systems which are actively used and recommended by Isil and other jihadists to assist, plan, co-ordinate and execute murders on a mass scale in Europe.
Telegram's founder, Pavel Durov, rejects calls to take down private Isil, Al-Qa'ida and Taliban chats, claiming that "the right for privacy is more important [to Telegram] than our fear of bad things happening, like terrorism".
Of course we need to balance the right to legitimate privacy with the requirement to prevent avoidable bad things happening. But for terrorists to be able to use social media sites as safe havens for their murderous plans tips the balance in their favour far too far.
We will not in the foreseeable future eliminate the scourge of international jihadi terrorism completely. But if the social media companies can be pressured into taking more serious efforts to reduce access by terrorists to their platforms, we will lower the risk of attacks. Preventing even a few can reduce widespread fear and insecurity and, more importantly, save lives. Ireland, as a responsible international player, must continue to be part of this joint enterprise.
Ivor Roberts is an advisory board member of the Counter Extremism Project and a former British Ambassador to Ireland
Catalan investigators yesterday raided the house of an imam in the town of Ripoll they believe may have overseen the cell which killed 14 people in twin terrorist attacks in Barcelona and the seaside resort of Cambrils.