In a comprehensive memorandum to government on November 18th, Garret FitzGerald outlined possible scenarios for Northern Ireland.
While his preferred outcome remained power-sharing and an Irish dimension, he was concerned at what he termed the "very grave danger" to the Irish government and the SDLP were the British to withdraw in circumstances which led to widespread civil war.
"Our own ability to act effectively in these circumstances is clearly extremely limited and might not even be sufficient to prevent the emergence of a de facto independent Protestant state in east Ulster or a de facto independent state controlled by the Provisional IRA in west Ulster."
FitzGerald acknowledged - as had been agreed by Dublin policy-advisers during the summer - that "the likelihood of effective intervention by the UN at our request in the event of sudden British withdrawal was not great".
However, he argued that the possibility of UN intervention "could be considerably greater" if it were aimed at preventing civil war and enjoyed the support of both northern communities and the British and Irish governments.
Given the danger to international peace "posed by the creation of a vacuum in the area as a result of a civil war", it was "not to be excluded that there would be a general willingness to assist in these particular circumstances".