The Irish government repeatedly urged the British to allow United Nations peacekeepers into Northern Ireland in 1969, according to documents released today by British National Archive.
But the forceful appeals by the-then minister for foreign affairs Mr Patrick Hillery were rejected on the grounds that Northern Ireland was a domestic British issue.
"HMG [her Majesty's Government] don't regard a UN peacekeeping force as either necessary or appropriate," one internal memo stated, just three days after the North erupted in violence at the August 12th Derry Apprentice Boys' march.
The files also highlight rising tensions between the Irish and British governments in the months leading up to the collapse of law and order.
Not only were both countries negotiating separately to join the-then European Common Market, but the Republic had a widening trade deficit with London - points regularly highlighted by British ambassador to Ireland Sir Andrew Gilchrist.
Britain sent troops into the North in April 1969 to guard key installations, but it was not until August that year that large contingents were deployed.
The Irish government urged London to ban the Protestant Apprentice Boys' march and allow in either a UN or an Anglo-Irish force.
However, the British government rejected all the proposals. When the larger-than-usual march went ahead on August 12th and, as predicted, descended into violence, tensions between the two governments reached a peak.
The Irish government condemned the attacks on Catholics and sent the Army north to the border.
The British embassy in Dublin was attacked and Sir Andrew warned that the IRA would take it as a signal to go to war.
Strong diplomatic notes were exchanged between London and Dublin each accusing the other of inflaming the situation.
The Irish government also called for the disbandment and disarming of the Ulster Special Constabulary - the infamous "B Specials" - accused by Catholics of being Protestant thugs in uniform.