The Government ordered armed forces to prepare an incursion into Northern Ireland to protect Catholics as violence there worsened in 1970, according to documents released today.
Army chiefs warned this would provoke engagement with much stronger British forces, and that it was also likely to provoke a counterstrike in the State by British troops.
Details of the directive were revealed in files released by the National Archives Office today under the 30-year rule of secrecy.
The order was issued following a crisis meeting of the Government on February 6th, 1970.
The Taoiseach, Mr Jack Lynch and his cabinet heard evidence from Catholic representatives from the North who feared widespread attacks on their communities by Protestants.
In an April 6th briefing paper marked "top secret", the Defence Forces' chief of staff, Lieutenant General Sean MacEoin, and his senior officers warned the government of "disastrous consequences" if they were ordered into Northern Ireland.
The Irish soldiers could have been outnumbered by more than 16 to one by a combined force of British troops and armed police units.
Army commanders also warned of possible reprisals by Protestant extremists against Catholic areas in Northern Ireland that could not be reached by troops from the Republic.
Then defence minister Mr Jim Gibbons told General MacEoin he had been instructed by the Cabinet to order the State's forces to "prepare and train the army for incursions in Northern Ireland if and when such a course became necessary".
This would arise in case of a complete breakdown of law and order in which security forces in Northern Ireland were "unable or unwilling to protect the (Catholic) minority".
According to one military file, Catholic groups from Northern Ireland sought weapons and ammunition from the Republic, "the provision of which the government agreed as and when necessary".
"Accordingly, the Chief of Staff was instructed to put truck loads of these items at readiness so that they could be available in a matter of hours if required," the document reveals.
In their assessment, the Army's general staff said the "execution of a directive to mount incursions in Northern Ireland would undoubtedly have the most serious military implications even when adequate strength and equipment could be made available."
The paper says that Ireland's defence force strength at the time was only 8,860 personnel, a number which included the air corps, navy, troops on UN duty, and back-up units.
"Excluding these elements there would not be more than 2,500 line troops available to be mustered, organised into units and trained preparatory to undertaking incursions," the document warns.
In addition, the paper says their combat effectiveness would have been low and there were deficiencies "in almost every type of armament, ammunition and military equipment".
The Irish forces would have faced 13,000 British troops in Northern Ireland as well as 8,500 police and reserves trained with firearms.
These could be immediately reinforced from Britain by another 20,000 troops with air and naval support.
"The armed opposition likely to be encountered by incursions into Northern Ireland is vastly superior in strength, organisation, combat training and equipment to those elements of the Defence Forces which could be mustered," army officers warned.
AFP