Or more plausible, British spies were behing PSF's peace strategy, and dismantling of PIRA. Donaldson was a staunch ally of Adams, and shared his politics, as did Scap. Are you too blind to see, that PSF's entire strategy, was most likely formulated by using spies and agents, to promote Adams , whilst purging those in the way.
MI5 /MI6 is a hugely powerful organisation, do you really believe they would tolerate rogue agents(securocrats

) working against the British agenda. Their feet wouldn't touch the ground. Look what happened others, who went against Blairs policies, like David Kelly, pre Iraq, or David Shayler.
MI5's strategy(normalisation and Ulsterisation) is almost identical to PSF.