At the birth of self-governing Ireland in 1922, the Republican Movement split down the middle over the terms of the peace deal with Britain. Purists committed to a Republic of all Ireland waged an internecine conflict with the moderates led by Michael Collins, the charismatic leader who had signed the peace treaty.
Collins said he had also signed his own death warrant and so it proved: he was shot dead in an ambush. But the moderates eventually prevailed, using far more ruthless methods than the British to smash hardline Republicans: 11,000 were interned and 77 executed in reprisals.
Another split occurred in 1926 when realists, who believed that the Irish Republic could be achieved by anti-imperialist politics rather than militarism, broke away from extreme Republicanism to form the Fianna Fail Party.
Its chief Eamon de Valera, swept to power in 1932, and did not hesitate to deal ruthlessly with Republican extremists, jailing and hanging them, and allowing others to die in futile hunger strikes.
For over 40 years a shrinking band of diehards kept alive the fantasy of Sinn Fein and the IRA as the legitimate power Ireland, but after the ignominious collapse of a military campaign against the Unionist state in the 1950s, a surprising re-think took place.
The by now tiny Republican Movement was steered by Moscow-leaning leftists towards social radicalism and away from nationalism.
Then the movement split again in the early 70s, between the Marxists, now the Official IRA, that eventually agreed a ceasefire with the British in 1972, and the Provisionals who still wanted to bomb the British out. But, by the end of the 1970s the armed struggle had reached an impasse. A Northern Republican group, led by Gerry Adams and Danny Morrison, decided to revive a moribund Sinn Fein and promote non-violent nationalism politically. When the 1981 Republican hunger strikes mobilised unprecedented popular support, they adopted a dual political and military strategy.
The morbid fear of politics subsided, and, by the early 1990s many military men were convinced a long war was unwinnable. The successful Adams-McGuinness partnership meant most backed the leadership's decision to negotiate with the British and the Unionists for powersharing and amnesty for prisoners.
If Sinn Fein names the hardmen, it is unlikely to lead to a split. The bombers in their madness killed Sinn Fein supporters in Omagh, and all Catholics could face Loyalist paramilitary reprisals.
Tom Gallagher is professor of ethnic conflict at Bradford UniversityReuse content