Since last autumn gardai have been warning that republicans opposed to the ceasefire have been planning to resume a violent campaign.
They also seemed to believe the new year was a likely time to start a campaign. Part of the reason for this was that they believed the dissident republicans wanted to put a distance of time between restarting their campaign and the Omagh atrocity last August 15th.
There were also strong suspicions that the "Real IRA" group, which carried out the Omagh bombing, had collapsed, but that a hard core of its members had developed links with the other anti-ceasefire element known as the "Continuity" IRA.
The Continuity group has existed for several years but has had a tiny membership and few arms or resources. It carried out a few bomb attacks on commercial targets in the Border area of Northern Ireland in the period of the first IRA ceasefire from 1994 to 1996, but nothing since. Its original leader, Michael Hegarty, is also a founder-member of the splinter political party, Republican Sinn Fein. He was arrested with explosives in Co Monaghan three years ago and is serving a lengthy jail sentence.
Gardai believe the leaders of the Continuity IRA have maintained a skeleton structure awaiting the day when disaffected Provisionals would seek an alternative way to carry on the "armed struggle".
The leaders of the Continuity IRA believe they are the true inheritors of the militant republican tradition stemming from the First Dail, and they accuse the Provisionals of having sold out on this ideal. In south Armagh, where both the Continuity and Provisional IRAs have members living close together, local people have reported heated disputes.
The Continuity group, like the "Real IRA", is still in the early stages of developing into a proper terrorist organisation and has no known significant fund-raising side, unlike the Provisional IRA and other Northern-based paramilitaries. As a result, it was always likely that the Continuity movement would resort to armed robbery, and on a large scale.
In May last year, the "Real IRA" tried to carry out a major robbery of a cash-in-transit van at Ashford, Co Wicklow, but this was intercepted by armed gardai, and one of the robbers was shot dead.
The Garda Special Branch had well-placed intelligence on the activities of the "Real IRA", but it would appear there are no sources of information on the activities of the group responsible for Monday night's robbery.
The Dalkey robbery could be the work of ordinary criminals or former republican paramilitaries who have banded together to enrich themselves.
But there are aspects of the robbery suggesting that dangerous amateurs, such as the kind of person who would be attracted to a dissident republican group, rather than professional terrorists or criminals, were involved. The presence of AK47 assault rifles is the most obvious. These are infantry weapons, preferred by terrorists but rarely used by ordinary criminals because they are bulky and hard to conceal. Criminals normally prefer machine-pistols, sawn-off shotguns or handguns for cash snatches.
It is believed the Continuity IRA has acquired a number of AK47s in the past year, including some taken from the Provisional IRA in Belfast.
The use of a 10-year-old Ford Granada with engine faults as a getaway car is another sign that this was not the work of a professional gang of robbers. After pulling off an elaborate and well-thought-out robbery, the gang members found themselves having to try and push-start the car supposed to carry them and £400,000 from the scene.
No gang of Dublin robbers would allow themselves to be caught short like this, having to forfeit almost £500,000 for the sake of a car worth only a few thousand pounds.
The rapid arrival of gardai on the scene prompted the robbers to abandon both the car and the cash.