Up to 1972 , the PIRA in Belfast effectively controlled many nationalist areas of the city , manning permanent checkpoints and barricades . These ' no-go areas ' , however , were re-taken by the British Army in response to the Bloody Friday bombings of 1972 , in a major operation named Operation Motorman . The British Army proceeded to build fortified posts in republican west Belfast , thus hampering the IRA 's freedom of movement . After this setback , Seamus Twomey , who had authorised the Bloody Friday operation , was replaced as Belfast Brigade commander by Gerry Adams , with Ivor Bell as his second-in-command . Adams held the post for ten months , before he was arrested and interned in July 1973 . The security forces managed to capture the next three commanders of the Belfast Brigade over the next year : Ivor Bell , who held the post from July 1973 to January 1974 , Sean Convey , who lasted just two months before being arrested in March 1974 , and Brendan Hughes , who was arrested in May 1974 . These setbacks were indicative of the pressure being put on the IRA in Belfast , which was hard-hit by arrests in this period . After 1972 , the numbers of soldiers killed by the IRA in Belfast fell consistently . In 1972 , the Provisional IRA killed 145 members of the security forces , most of them in Belfast . By 1974 , this figure had fallen to 40 . Moreover , the Belfast Brigade changed its tactics in an effort to avoid the heavy losses in killed and captured they had suffered up to that point . According to journalists Patrick Bishop and Eamon Mallie 's book , '' The Provisional IRA '' , " As a result of the many arrests and increased Army presence , prolonged engagements with the Army faded out and were replaced with single shot sniping . " In addition , " the revulsion caused by Bloody Friday persuaded the Provisionals to gradually abandon the car bomb . " Partly as a result of the losses they suffered through arrests in this period , and partly as a result of secret negotiations between the IRA leadership and the British government , the Provisional IRA called a ceasefire from January 1975 to January 1976 . The Belfast Brigade in general welcomed this respite . Under the terms of the ceasefire it ceased offensive operations against the security forces . In return , the British government funded ' incident centres ' , or offices for Sinn Féin in nationalist parts of Belfast , hoping to encourage the development of the Provisional republican movement 's political wing over its military wing . In practice , however , the ceasefire brought little diminution of the violence in Belfast
Bloody Friday
Bloody Friday (1972)
Provisional IRA Belfast Brigade