The raids by Garda anti-terrorist officers were part of an overseas investigation into support cells for jihadi activists. It underlines once again that while Ireland may be an extremely unlikely target for an attack by international terrorist groups, it can be used by sympathisers to provide logistical aid to potential killers elsewhere.

In the past, this country has been used by al-Qa'ida sympathisers, who provided logistical support for active cells overseas by assisting with fundraising and producing false identity documentation, including highly valuable Irish passports, that could be used in other countries to help prepare for an attack.

The man arrested yesterday is suspected of committing an offence under anti-terrorist legislation, which was introduced here in 2015. It created three new crimes of publicly provoking an act of terrorism, helping recruit terrorists and training them.

Police sought assistance of gardaí after inquiries in other European countries disclosed possible involvement of a Dublin link to support cells.

Raids were also carried out in Limerick and Wexford last June when officers seized social welfare documentation, which had previously been connected to Rachid Redouane, who was shot dead by police shortly after the terrorist attack on London Bridge.

Officers discovered a British identity document on his body.

He had obtained the document with the help of an EU residency card, which Redouane had acquired while living in Dublin previously.

He left this country in September 2015 and returned to the UK. He later visited a number of other countries, including his native Morocco, when he developed close links with other terrorists.

Redouane's development from an innocent chef into an active terrorist illustrates why gardaí have to be fully alert here to the dangers posed by jihadis, even if we are not the victims of their atrocities.

The Government has to continue providing the resources to allow gardaí to develop the response to international terrorism.

They must also keep focus on the enemy within - dissident republican groups and, in particular, the New IRA, which is now seen as posing the biggest threat to security on the island since the dark days of the Provisionals.

Irish Independent