Among the highlights of the 1975 documents is the revelation of public figures, after a spike in oil prices, warning sternly that "the days of cheap energy are gone".

European foreign ministers behind closed doors debated the fallout of a US military withdrawal from an unpopular war, at a meeting hosted in Ireland, in which the French were the most anxious to tell the Americans, "we told you so". Campaigners were warning that small farmers would be squeezed out of business by decisions taken in Brussels.

Fianna Fail had a think-in and produced a discussion document about the role of women in Irish society, though childcare as we understand it today didn't feature. A file marked 'Dublin suspicious of IRA truce and its attendant circumstances' could have come from the desk of Michael McDowell last week.

The term of the Fine Gaelled coalition government led by Liam Cosgrave was shaped by the oil crisis that hit all western countries when Opec halted oil shipments to countries it felt had backed Israel in the 1973 Yom Kippur War. Oil, conservation and alternative energy sources . . . though less sexy than the ongoing and interminable drama of the North . . . were gripping day-to-day decision-making in the government and infusing it with a near-apocalyptic pessimism.

This wasn't helped by an international embarrassment for Ireland, about to take on the presidency of the European Community for the first time, when in late 1974 a spill from a Liberian oil tanker at Whiddy Island in Bantry Bay contaminated 30km of coastline.

The New York Times published a savage critique of the incident, and Ireland's relationship with foreign oil companies, which could have been lifted from supporters of the Rossport Five who feel that Ireland isn't getting enough out of Shell for the rights to the Corrib Gas Field off Mayo.

The article, by an Edward A O'Neill, was transcribed in a 27 December 1974 cable sent back to Dublin from the Irish consulate in New York and furiously forwarded to dozens in government. It excoriates the Irish government for making the worst possible deal with Gulf Oil, which owned the terminal, netting just $205,000 a year, "about the salary of an upward-mobile vice president in Gulf 's headquarters in New York".

The end of the cable relates that O'Neill was working on a novel in which Bantry Bay figured. The novel, The Rotterdam Delivery, featuring a disaffected IRA terrorist who helps the Dutch government to hijack an Arab oil tanker bound for Whiddy Island, was indeed published in 1975 and was promptly (and deservedly) forgotten.

That same month, finance minister Richie Ryan went before the Dail at 7.30pm on 4 December 1974 to announce a steep rise in petrol prices, following 12 months in which the cost of home heating oil had doubled and petrol had gone up "just" 50%. His message, beyond the immediate rise in prices, was grim. "The days of cheap energy are gone, " he said. "We must adapt our lifestyles in recognition of this fact."

While it is difficult to imagine a cabinet minister speaking so bluntly today, events as they unfolded in 1975 triggered dramatic and radical steps that may yet be echoed in our not-too-distant future.

Following a strike by lorry drivers and a sympathy walkout from dock workers, oil imports into Ireland were frozen altogether. An emergency meeting of ministers on 26 April 1975 resulted in plans being drawn up for the army to seize control of oil deliveries to ensure the continuation of supply to designated vital sectors including the gardai and defence forces.

Lingering in the background was a fear that the shipments could become targets for "subversives".

A memorandum from that meeting also reveals that the Department of Transport and Power had sought the co-operation of the four major oil companies in facilitating an army takeover of oil deliveries, but the companies "were doubtful about cooperation being forthcoming unless and untilf the mood of the country had turned clearly against the strikers".

Another result of the crisis was a ruthless pragmatism. A 29 April note to the file of the Department of Transport and Power notes that the ESB was given permission "to undertake overseas consultancy and advisory service work". The first client for the ESB . . . named but without noting the loaded geopolitical implications . . . was Saudi Arabia. In minutes of an internal department meeting of 11 April, Iran and Iraq were also mentioned as prospects.

This sudden importance of the Middle East to Ireland was not lost on the Department of Foreign Affairs either.

When Henry Kelly of the Irish Times let it be known he was planning a trip through Beirut, Cairo and Tripoli for a special supplement on the region, it generated major traffic between Iveagh House and various embassies in Arab capitals, which bent over backwards to facilitate meetings with local business and government contacts.

Ireland held the presidency of the European Community for the first time in the first half of 1975, a major test of the ability of the government and civil service to play a full role in Europe. Files detail preparations stretching back to 1973 to get ready for the events of those six months.

Garret FitzGerald, then Minister for Foreign Affairs, proved more than able for the task, trying to guide a nascent common European response to the fall of Saigon to the Vietcong on 30 April 1975, marking a humiliating end to the US presence in the country.

But the discussions chaired by FitzGerald changed from a focus on how to deal with a humiliated US to the burgeoning humanitarian crisis, when thousands of so-called "boat people" fled the country fearing reprisals from the new communist regime.