As a self-styled terrorist is jailed, James Freeman looks at the questions he leaves behind

Whatever happens ultimately in the Adam Busby affair, a major question will always hang unanswered in the air like a persistent stink, and that is why Busby was allowed to remain at large in Dublin for 13 years, plotting, and fomenting trouble for the British state.

The answer, according to his former cohorts in the Scottish Republican movement, was that he was deliberately left there, watched but unharmed, because his antics were damaging to the image of Scottish nationalism.

This is not a new charge. A parallel is the persistent allegation, much more than a mere suspicion, that agents provocateur were widely used in the sixties, seventies and eighties by the Special Branch and the Security Service first to infiltrate extreme Scottish republican organisations and then to give evidence against individuals when their conspiracies unravelled. In Busby's case, time and again he gave interviews to journalists not so much admitting but proudly proclaiming his activities over the years, yet the authorities in both countries seemed to turn blind eye and the letter bombs continued.

Donald Anderson, the retired Glasgow schoolteacher who was in with Busby at the founding of the Scottish Republican Socialist Party and who was himself tried and acquitted on explosives charges, says: ''I cannot say if Busby was a Branch plant but he has certainly been responsible for an emormous amount of damage to the broader cause of Scottish nationalism. He has been very, very useful to the British state in their quest to keep the Union intact.''

Adam Busby was a founder member of the SRSP, a quasi-respectable fringe political party, although it will always be associated with the wilder shores of nationalism. It is, however, possible to chart Busby's course from harmless fringe political activist in pre-SRSP days to dangerous letter bomber.

Originally, says Donald Anderson, they had all been members of the John McLean Society but it, embracing as it did the extremely hard left, had never been remotely sympathetic to the idea of Scottish independence. In the convoluted history of minor fringe political splits there was nothing unusual in the founding of the Scottish Republican Socialist Clubs in the early 1970s and the subsequent splintering off of the Scottish Republican League.

When that organisation petered out the disaffected trickled back to the Clubs, until Busby came up with the idea of the SRSP. The close detail of what took place in fringe republicanism, is disputed but the key factor appears to have been that much of the debate was carried on in pubs .

Busby appears to have been incapable of holding down a job. In the early eighties he was a barman in a pub off Great Western Road, until his drinking habits caught him out. Always on the scrounge for drinking money, Busby homed in on the late Willie McRae. McRae, who was found shot through the head beside a Highland road, has entered Scottish mythology.

The alleged incident which led to Busby's defection to Dublin is typical of his style. In the summer of 1983 republicans from the SRSP had decamped to Berwick-upon-Tweed to protest, it was on their arrival that Busby allegedly sprayed a slogan on the side of a Royal Navy recruiting display van.

He subsequently alleged that he and David Dinsmore, a 20-year old extremist from Falkirk who later faced a charge of posting a letter bomb to the Earl of Mansfield at Scone Palace, fled Scotland because they feared they would be labelled major terrorist conspirators by Special Branch and would end up with 20-year sentences. Probably closer to the truth, Donald Anderson believes, is that Busby had run out of people who would tolerate him.

Busby was eventually arrested for shoplifting a tin of ham from a Dublin city centre store.

Busby claimed his arrest was a ruse to force an extradition attempt from which he was confident he would walk free.

This legal device, putting themselves and the authorities in both countries on the spot, was to cost Bubsy and Dinsmore eight months in jail. The cost of fighting the action, allegedly into six figures, Busby claimed, was financed, he again claims, partly by bank robberies carried out by supporters in Scotland. That, say other Scottish republicans, was utter nonsense. When it became apparent to Dinsmore that he might lose his appeal he fled to the Continent.

On March 17, a letter bomb got through to Defence Secretary John Nott, possibly the first time the SNLA made a public move,By the following year, Busby states, the SNLA were issuing an attack or a hoax every few days - 27 devices in a row.

But, Busby admitted, Siol nan Gael was by now disintegrating. The decision to flee to Dublin was deliberate and carefully planned, he maintains, but the events have the same stamp of fantasy.

Busby's ''political'' career began on his 16th birthday when he joined the SNP. He had been brought up in Old Kilpatrick, Dunbartonshire. He went on to join the Argyll and Sutherland Highlanders after an unhappy schooling at Clydebank High.

Once demobbed he became involved with Dumbarton Young Scottish Nationalists and he fell under the wing of Major Frederick Boothby - very probably one of the agents provocateur used by the State to infiltrate the republican fringe. Boothby was later jailed for three years in one of the celebrated trials involving Scottish republican terrorists .

Busby became a Gaelic-language activist and drifted into Siol nan Gael, the group which the SNP was later to proscribe for activities bordering on the paramilitary. Seed of the Gael's national organiser was David Dinsmore.

Siol nan Gael was also the recruiting ground for Peter Wardlaw's Army of the Scottish People whose bank robbing and bombing activities resulted in sentences totalling 72 years. It now appears that these events of 1980, coupled with the slough of post-referendum despond into which Scotland had descended, were the trigger for the founding of the Scottish National Liberation Army. There is very little evidence to suggest that the ''Army'' ever consisted of many more than Busby and Dinsmore.

Although their letter bombs were just as liable to be hoaxes, police dismissed the notion that the devices were the the work of amateur cranks, which makes it all the more inexplicable that more serious efforts to halt Busby were not made much earlier.

Yet Busby says that no effort was made to extradite he and Dinsmore from Dublin in the early days. When asked whether he was merely a fantasist, Busby said: ''We are still here 11 years on. That's a lot of fantasy.''