The IRA has taken considerable heart from meetings with British politicians, believing such encounters are signposts to the time when, according to one of its articles of faith, a government will sit down to negotiate a British withdrawal.
The memory of past meetings is cherished by republican leaders, who cite them in support of their argument that the Government's present attitude is not based on any fundamental principle and is therefore open to reversal.
At the meetings IRA spokesmen are generally concerned to make one point above all others: that there will be no weakening of the organisation's resolve to maintain its campaign of violence. Those they meet tend to come away disillusioned and disheartened and do not usually request further encounters. As a result, the meetings are normally one-off affairs.
Ministers and senior politicians have met republican leaders occasionally over the years, but for more than a decade the official attitude has been that both the IRA and Sinn Fein, its political wing, will be treated as beyond the pale unless they renounce violence.
This line has been strongly supported by successive Irish governments, which have taken the view that British contacts with republicans are potentially destabilising in that they tend to undermine the authority of Dublin administrations. The Labour Party is also against talks with republicans.
The contacts began in the early 1970s with Harold Wilson who, while in opposition, met IRA leaders for talks in Dublin. The most formal face-to-face meeting between a government and the terrorists came in 1972 when William Whitelaw, the then Secretary of State for Northern Ireland, met IRA leaders, including Gerry Adams, for secret talks in London.
The IRA said the only purpose of the meeting was to demand a declaration of intent to withdraw from Ireland. Like Gordon Wilson, Mr (now Viscount) Whitelaw was disappointed to find the republicans inflexible and unbending, recalling later that their mood was one of 'defiance and determination to carry on until their absurd ultimatums were met'.
More systematic contacts took place with the Labour administration in 1974-75, with a series of meetings between officials and Sinn Fein which led to a temporary ceasefire. Another encounter came in 1978, when Douglas Hurd, now Foreign Secretary but then acting in his capacity as an individual MP, met Gerry Adams in Belfast.
The IRA yesterday admitted responsibility for Wednesday's bombing outside a Conservative club in central London. In a statement issued in Dublin, it said it planted the device outside the club in Argyle Square, which caused little damage.