Exercise Armageddon Exercise Armageddon , also described as Operation Armageddon , were plans by the Republic of Ireland drafted in September – October 1969 that envisaged a military invasion and guerilla operations in Northern Ireland during The Troubles , in order to protect the Catholic communities during rioting . Background . The Northern Ireland Civil Rights Association organised protest marches from 1968 seeking to improve conditions for Roman Catholics in Northern Ireland , who were discriminated against by the majority Protestant population . This had led to counter - protests and then sectarian riots , leading to 1 , 500 Catholic refugees moving south to the Republic of Ireland . The Government of the republic wanted to help in some way , and on 13 August 1969 the Taoiseach , Jack Lynch said in a television interview : " . . . the Irish government can no longer stand by and see innocent people injured and perhaps worse " . His cabinet was divided over what to do , with Kevin Boland and Neil Blaney calling for robust action . On 30 August Lynch ordered the Irish Army Chief of Staff , General Seán Mac Eoin , to prepare a plan for possible incursions . While the riots continued , the introduction of British Army troops in the Falls area of Belfast , and around the Bogside part of Derry from mid - August under Operation Banner protected the Catholic communities from further such attacks . Therefore the planning of Exercise Armageddon into October 1969 was superseded by events and did not reflect the reality on the ground . The plan . The army ' s planners accepted that it had " no capability to engage successfully in conventional , offensive military operations against the security forces in Northern Ireland " to protect the Catholic minority from loyalist mobs . The plan called for units of specially trained and equipped Irish commandos to infiltrate Northern Ireland and launch guerilla - style operations against the Belfast docks , Aldergrove airport , the BBC studios and key industries . The campaign would start in Belfast and the northwest , so as to draw the bulk of security forces in Northern Ireland away from the border areas and turn their attention to the guerrilla campaign . The Irish Army would then invade with four brigades operating in company - strength units to occupy the Catholic areas of Derry and Newry , and attack any remaining security forces in those areas . The Irish Army Transport Corps did not have enough resources to transport all of the necessary forces to the conflict zone , and the plan suggested hiring buses from Córas Iompair Éireann . As an element of surprise was required , Ireland would not formally declare war when the operation started . However the planners also accepted that only 2 , 136 troops out of 12 , 000 in the army were at actual combat readiness . The operation would leave the Republic of Ireland exposed to " retaliatory punitive military action by United Kingdom forces " . The plan included a warning that : " The Defence Forces have no capability of embarking on unilateral military operation [ sic ] of any kind . . . therefore any operations undertaken against Northern Ireland would be militarily unsound . " Critique . The 2009 documentary " If Lynch Had Invaded " interviewed a number of academics and former civil servants and Irish army officers , and they highlighted a number of surrounding aspects : Historian Diarmaid Ferriter considers that the operation would have been popular at the time , given the strong emotive feeling in the Republic about the situation in Northern Ireland . Arms Crisis . Subsequently some more actively nationalist Irish Ministers were tried in 1970 in the Arms Crisis trial , where the defendants included an Irish army officer . It emerged that a secret Irish government fund of £100 , 000 had been dedicated to helping the refugees , but some of it had been spent covertly on buying arms for paramilitary groups . Ministers Charles Haughey and Neil Blaney were sacked from their posts .