i don't know if you've read the secret history of the ira by ed moloney - if you haven't you should. in sum the book's thesis is that for many years adams and mcguinness and their faction had been running down ira activity in the furtherance of their peace strategy. anthony mcintyre's 'good friday: the death of irish republicanism' is another good read, a collection of articles focusing on sinn fein's betrayal of their constituency and principles. and richard rawe's two books about the hungerstrikes are well worth reading, showing how adams prolonged the hungerstrikes for electoral advantage. so, central figures in the leadership of sinn fein and the ira were calling the shots in a way which secured their position but undermined the armed struggle as sinn fein replaced the ira as the primary organisation in the provisional republican movement.
so while it would have been difficult to 'win' militarily, the provisional movement's leadership actively worked against those within the movement who opposed their agenda, with the republican sinn fein split, with the expulsion of ivor bell, with - some say - the deaths of the eight volunteers at loughall. there's been a great deal to come out over the past 20 years which shows adams and mcguinness in a less than flattering light.