The full inside story about the IRA's failed Marita Ann gun running operation is revealed for the first time in John Crawley's new book.
'The Yank: My life as a former US Marine in the IRA' tells how the republican movement used Boston mobster James 'Whitey' Bulger and his criminal connections to help source and transport a huge haul of weapons to Ireland in 1984.
The arms, which left the US on a trawler called the Valhalla, were later transferred in the Atlantic Ocean to another vessel, the Marita Ann, before it was boarded by waiting Irish authorities and the shipment was seized.
Mr Crawley was one of three men, including former Sinn Féin TD Martin Ferris, convicted for their part in the plot.
Former IRA man, Garda Special Branch and MI5 informer, Sean O'Callaghan is believed to have betrayed the plan.
Mr Crawley, an ex-member of the US Marine Corps special forces, believes Mr O'Callaghan wasn't the only informer and others based in Ireland also provided information.
Sent to the US with £9,000 by former Deputy First Minister Martin McGuinness, Mr Crawley's mission was to put together a huge shipment of arms for use by the IRA.
He reveals that he was reluctant to take on the task partly because he was due to link up with a highly active IRA unit led by Monaghan republican Jim Lynagh, who was killed in 1987 during an SAS ambush in Loughgall, Co Armagh.
After travelling to the US he later returned to update the republican leadership and provided a list of weapons he hoped to acquire to three members of the IRA 'Army Council' - including the man he believed was the then Chief of Staff.
Although he had knowledge of the US operation, Mr McGuinness was not present at the meeting.
In his book, which is being published on both sides of the Atlantic, Mr Crawley writes that despite the senior republican's reputation as a "military thinker" he became increasingly frustrated by what he described as "his military illiteracy".
The wish-list presented to the 'Army Council' members included the 106-millimetre recoilless rifle, an anti-tank weapon Mr Crawley believed could have been used to demolish British army watchtowers in south Armagh, sink Royal Navy patrol vessels in Carlingford Lough and damage other military and police installations.
Other items listed included assault rifles, heavy machine guns, military grade mortars RPG-7 and Sam-7 surface-to-air missiles.
While in the states he was introduced to James 'Whitey' Bulger, who at the time was one of the most ruthless mobsters in Boston.
Mr Crawley reveals that Bulger, who was murdered in a US jail in 2018, provided the IRA with cash, weapons and access to his crime network.
Johnny Depp told the story of Bulger in the 2015 blockbuster Black Mass.
Mr Crawley reveals how Bulger would offer his opinion on IRA operations and suggest potential targets.
The former IRA man explains how at times he had to "walk on eggshells" when around Bulger, who once asked him how to make an under-car booby trap bomb.
He writes how he fobbed the gangster off and remained wary of him.
"I never trusted him and could never relax in his company," he wrote.
** 'The Yank: My life as a former US Marine in the IRA' by John Crawley and published by Merrion Press is available to buy now.