Border security: The intensification of the conflict in the North in the early 1970s with consequent spill-over effects in the Republic meant that the number of Army/Garda checkpoints increased from 11 in September, 1972 to 641 in March, 1973.
An Army intelligence document, released for public view in the National Archives under the 30-year rule, charts the rise in tension on a month-by-month basis, as reflected in the number of checkpoints (see table).
Eleven vital installations required a full-time military presence, including Government Buildings, industrial plants likely to contain explosives, RTÉ's transmitter at Athlone, Co Westmeath and various ESB power-stations. On the instructions of the Minister for Justice, commercial explosives were also stored in 12 Army barracks and large quantities were only moved under military escort.
Troops received special training to deal with what the document calls "contingencies which may arise from the present internal security situation". Such contingencies might include: "Serious incursions in Border area(s), serious violence in Dublin or other large cities, major demonstrations or threats to the Curragh Detention Barracks [where some republican prisoners were held].
The atmosphere of the time is reflected in a report from an Army officer who wore civilian clothes while he monitored the funeral of an IRA member, Dermot Crowley from Cork, who was killed in an explosion near Omagh, Co Tyrone in June, 1973. The funeral stopped on its way through Cavan, "because driver of hearse refused to go any further without his dinner".
Gardaí identified one of the sympathisers as a leading IRA member and arrested him: "When arrested he shouted to a companion - 'Get a Belfast Unit in here - we have targets down here now'."
But not all activities were directed against the IRA and a further report from a Cavan-based infantry unit describes how "two uniformed armed members of the Royal Ulster Constabulary were stopped and questioned" at a Border checkpoint. "They were driving in an unmarked official car." The document states that, three weeks earlier at this location, a shot was fired by "uniformed armed men" at a passing civilian and that this was the reason the checkpoint was established at this place.
Under the heading, "Cross-Border Traffic in Arms", an Intelligence document in the file lists quantities of illegal arms and explosives found in the Republic between August 1969 and June 1973. These include: 10 tons of explosives; 157 rifles (including a dozen Armalites); 61,414 rounds of ammunition and "one cannon plus 17 shells".
"These weapons were generally located in Border areas - counties Donegal, Sligo, Leitrim, Cavan, Monaghan and Louth but some were found in counties Cork, Kerry, Limerick and Longford."
The document, dated "June 1973", stated there was no evidence that the IRA was smuggling large quantities of arms and explosives into Northern Ireland through the Republic. "It is also known that in some areas in the Republic 80 per cent of listed Provos have never handled a military-type weapon."