Newly released Department of Justice files show that British diplomats appealed for the Army to be called out to help Gardaí prevent the burning of their Embassy in Dublin in 1972.
But the authorities decided that bringing armed troops onto the streets would only make the situation worse.
The official garda report on the incident also claimed that the declaration of a day of national mourning for the victims of Bloody Sunday had contributed to the burning of the Embassy.
The Department of Justice files on the burning of the British Embassy in 1972 were only released today, after being delivered late to the National Archives.
They reveal that on the day the Embassy was burned down, British diplomats requested that the Army be called out to reinforce the Gardaí.
On the morning of 2 February 1972, as crowds gathered outside the Embassy, diplomat John Williams warned that the Gardaí would not be able to prevent the building being burnt without Army support.
A similar request was made by the Foreign Office in London.
As the numbers in Merrion Square continued to build up, Mr Williams phoned the Department of Foreign Affairs again to warn that he was "increasingly apprehensive" about the situation, and was going to evacuate the building.
The official Garda report, released today, says that while they considered calling out the Army, it was felt that bringing armed troops on to the streets would only make the situation worse.
The report also states that the burning of the Embassy could not have been prevented, particularly because 2 February was officially declared a day of mourning, which "seemed to incense all otherwise moderate persons and whipped them into acts of remorse and oppression against the embassy building".
The report also says that Gardaí had information that if the Embassy had not been burned down, subversive organisations would have attacked it again with explosives.
