in 2008 that a British withdrawal would have caused civil war, as Loyalists would have expected the Republic to invade Northern Ireland. Peter Ramsbotham, British Ambassador to the United States, warned of a hostile American reaction. The British so wanted to leave Northern Ireland in 1975, however, that only the catastrophic consequences of doing so prevented it. The Irish government so dreaded the consequences that FitzGerald refused to ask Britain not to withdraw—as he feared that openly discussing the issue could permit the British to proceed—and other members of government opposed the Irish Cabinet even discussing what FitzGerald referred to as a "doomsday scenario". He wrote in 2006 that "Neither then nor since has public opinion in Ireland realised how close to disaster our whole island came during the last two years of Harold Wilson's premiership", and in 2008 said that the Republic "was more at risk then than at any time since our formation". Mid 1970s In February 1974, an IRA time bomb killed 12 people on a coach on the M62 in the West Riding of Yorkshire. Merlyn Rees, the Secretary of State for Northern Ireland, lifted the proscription against the UVF in April 1974. In December, a month after the Birmingham pub bombings killed 21 people, the IRA declared a ceasefire; this would theoretically last throughout most of the following year. The ceasefire notwithstanding, sectarian killings actually escalated in 1975, along with internal feuding between rival paramilitary groups. This made 1975 one of the "bloodiest years of the conflict". On 5 April 1975 Irish republican paramilitary members killed a UDA volunteer and four Protestant civilians in a gun and bomb attack at the Mountainview Tavern on the Shankill Road, Belfast. The attack was claimed by the Republican Action Force believed to be a covername used by Provisional IRA (IRA) volunteers. On 31 July 1975 at Buskhill, outside Newry, popular Irish cabaret band the Miami Showband was returning home to Dublin after a gig in Banbridge when it was ambushed by gunmen from the UVF Mid-Ulster Brigade wearing British Army uniforms at a bogus military roadside checkpoint on the main A1 road. Three of the bandmembers, two Catholics and a Protestant, were shot dead, while two of the UVF men were killed when the bomb they had loaded onto the band's minibus detonated prematurely. The following January, eleven Protestant workers were gunned down in Kingsmill, South Armagh, after