Drug trafficking is borderless - so it's time for the Gardaí to have boots back in Spain
Enterprising Irish criminals were first lured into mainland Europe by a potential tenfold increase in profits from drug deals, thus eliminating the middleman.
Over the previous decade, the gangsters had carefully built up valuable networks of contacts in European countries such as Spain, the Netherlands and Belgium. Through these, they had gained access to global underworld figures in South America.
But they had to pay a hefty price to their contacts for that access - and they quickly realised they had to be closer to the action if they wanted to become major players.
From their new continental locations, the Irish gangs built up a power base and were soon able to eliminate the Spanish and South American go-betweens to deal directly with the Colombians themselves.
They quickly established themselves in the importation of drugs from South America and places such as Morocco.
The gangs invested heavily in those shipments and took part in joint enterprises. Dozens of Irish criminals began operating in Europe.
The vast profits allowed them to develop a luxury lifestyle, acquiring mansions and expensive cars in Spanish sun spots, such as Marbella and Puerto Banus, while others established boltholes in the Netherlands.
The activities of crime barons like Christy Kinahan and his associates eventually attracted the attention of the police - and it was decided to plot a co-ordinated response involving several forces.
The garda authorities availed of the opportunity to badly dent the drugs pipeline into Ireland. They responded with "boots on the ground", rather than intermittently discussing the problem through liaison officers at Europol and Interpol level.
Detectives from the then Garda National Drugs Unit were deployed to Spain and worked with the Spanish officers in Operation Shovel, which specifically targeted Kinahan and Co.
A senior officer recalled: "Co-operation between the gardaí and other police forces in Europe became second to none as a result of the face-to-face contact and allowed us to focus directly on the Irish gangs involved in trafficking drugs that ended up in Ireland.
"Drug trafficking had always been a borderless crime for the gangs, but now it had become more or less borderless for us, as the co-operation allowed us to overcome legal obstacles."
Operation Shovel badly disrupted the Irish network and there were fewer shipments arriving here.
Gardaí accept that this was partly due to the recession, in terms of the demand for cocaine, but said seizures of key shipments that arose from the intelligence gathered in Spain also led to the fall-off in traffic.
Meanwhile, close links between garda drug officers and their counterparts in the Netherlands, through Operation Majesty, yielded major dividends in October 2013, when gardaí, with the Rotterdam organised crime unit, smashed a drug-trafficking network which had brought more than €40m worth of cannabis into Ireland and the UK.
Another major shipment was seized months later when the contacts between the Irish and Dutch units led to a monitoring operation on Irish suspects being put in place within two hours, rather than gardaí having to wait for requests for help to be rubber-stamped through the bureaucratic process.
The huge amounts of money involved inevitably led to a falling out and turned the Costa del Sol into a battleground, culminating in the murder of Gary Hutch last September.
Last Friday, that battleground moved back to Dublin, where Kinahan associate David Byrne was shot dead in the Regency Hotel. This was followed by the revenge murder of Eddie Hutch Senior on Monday.
There was no intelligence available to the Gardaí that the spiral of violence was about to return home. There is no way of knowing whether that intelligence vacuum might have been filled if the Gardaí had continued to have 'boots on the ground' in places such as Marbella.
But it might be time to reassess current policies, rather than relying on a single liaison officer based in Madrid to monitor developments there.