Undercover soldier's memoirs shine a light on intelligence war in Northern Ireland
Sean Hartnett's tale of his time in the Army proves technology still can't replace agent-handling, writes Henry McDonald
Novelists such as Graham Greene and John Le Carre have noted in the past that spying can produce exceptional works of literature. The American writer Philip Roth has even described Le Carre's autobiographical portrayal of the father-and-son duo in A Perfect Spy as "the best English novel since the war".
Greene's observation that all good writers must have a sliver of ice in their hearts could also equally apply to master spies, given both types of character have to mask their true selves, be magpie-like in picking up information and observing the lives of others and generally living a double life.
Spies can also produce fine, illuminating works of non-fiction. And Sean Hartnett's new book, Charlie One, certainly fits the bill.
From 1998 to 2005, the Cork-born recruit into the British Army's secret military intelligence unit known as 'the Det' lived his life in the war of the shadows.
He planted listening devices and secret cameras in hospitals, the homes of senior Sinn Fein figures like Raymond McCartney, the cars belonging to Real IRA operatives and the weapons hides of republican dissidents and Ulster loyalists.
His seven years of service resulted in the 40-year-old leaving the Joint Communications Unit Northern Ireland - formerly the controversial Force Research Unit - suffering from post-traumatic stress disorder (PTSD). His memoir, in fact, was the product of the therapy he underwent to help him cope with his PTSD.
His counsellor suggested he write down many of the experiences - some of them quite harrowing - which he endured while operating as an undercover spy tracking the Real IRA and also UDA hit teams that were detailed to kill, among others, Johnny Adair.
These jottings became Charlie One, and we should be grateful for his counsellor's advice - given that Hartnett has provided us with yet another shaft of light to illuminate the secret, often deeply dark, world of the undercover war in Northern Ireland.
Although he is a technological surveillance expert, having been trained in the Royal Signal Corps, Hartnett's book questions the efficacy of technical intelligence alone as the key weapon in counter-terrorism.
Indeed, one of the most disturbing stories in the book concerns the Real IRA murder of civilian security guard David Caldwell in 2002 at Caw Territorial Army camp on the Limavady Road outside Londonderry.
According to Hartnett, his unit in Derry, known as 'North Det', had electronic intelligence that the Real IRA was moving an explosive device out of the city to be used in an attack on an unspecified military security target in the north of the province.
As a result, Hartnett's unit put tracking devices on two cars that the Real IRA were using to transport an improvised explosive device (IED).
Despite having the advantage of a listening/tracking device, human error resulted in the car carrying a lunchbox containing the IED slipping through the security net and the bomb ultimately being left at the perimeter fence at Caw TA base.
The result was that David Caldwell picked up the lunch-box and the device exploded, leaving him with mortal wounds that led to this death a few days later in Altnagelvin Hospital - the same hospital Hartnett had planted another listening device inside the very same year.
The lesson from reading Charlie One is that human intelligence, or 'humint' as it is known in security circles, is still the vital component in the counter-terrorist machine.
In practice, this involves the recruitment and running of informers on the basis of bribery, blackmail, or, in the case of Britain's super-spy within the IRA, Freddie Scappaticci, having a 'walk-in' who volunteers to become your agent.
Of course, humans are guilty of misjudgements and mistakes, but still the most prized intelligence assets a state security agency can control are other humans who are prepared to betray their comrades and their cause.
The other striking thing that you learn (or, perhaps, have reconfirmed to you) from Charlie One is the extent of penetration the British state had among the paramilitary forces - republican and loyalist - within Northern Ireland.
None of this spying apparatus has been disbanded, or wound down, Hartnett claims, with surely some authority.
It is now being directed at the New IRA and the other republican dissident groups opposed to the power-sharing settlement here.
Hartnett insists that some of his former colleagues have taken their know-how and their technology to the secret war against Islamic State and its offshoots in English cities with large Muslim populations.
The type of technological spying equipment at the state's disposal was 10 years ahead of its civilian equivalent when Hartnett joined up at the end of the 1990s, he says.
Just imagine, therefore, how sophisticated, covert and near-invisible the latest technical surveillance cameras and bugs that the state must have in its armoury these days.
"You wonder why they bother," exclaims Hartnett, when he reflects on the ongoing terror campaigns of the hardline republican organisations.
The answer to that is, of course, the power of ideology and the notion of unfinished business in terms of the Northern Ireland's continued existence, partition and the inability of the Belfast Agreement to deliver Irish unity.
It is still a potent force in driving the disaffected and the alienated into the arms of organisations that offer them a meaning to their otherwise empty existence.
Spying, blackmailing, agent-recruiting and electronic surveillance play a key part in grinding down terrorist campaigns. But it cannot succeed in ending the war alone - that requires the primacy of politics and the possibility of alternative strategies for those who want to give up pursuing their objectives via violence.
Yet even if you accept the above, you can still understand the Cork man's incredulity when it comes to why the armed republican groups keep going.
His memoir is not only an exorcism of his ghosts, an exercise in personal therapy. It is also a warning to the next generation - especially those devouring unquestionably the more romanticised and simplistic portrayals of the 1916 Rising this year - that, in Hartnett's own words, the "armed struggle" will "only end for you in Maghaberry or Milltown".
Charlie One: The True Story of an Irishman in the British Army and his Role in Covert Counter-Terrorism Operations in Northern Ireland is published by Merrion Press