The attacks on New York and Washington may well have an impact on the Northern Ireland peace process, since the Bush administration is bound to review its attitude towards Sinn Fein and the IRA.
Although one cannot yet say whether the airliner attacks will lead to a sea-change in Washington's attitude, the United States will obviously develop a new and tougher attitude towards armed groups. The key question is whether this will encompass the IRA. The republicans will initially be thanking their lucky stars that they have no known association with Osama bin Laden.
But America has already been pressing republicans for an explanation of the role of the three Irish republicans who were arrested last month in Colombia, and on links with the Farc guerrillas there. So far as is known, no such explanation has been provided.
This has already cast a shadow over Sinn Fein, since Washington regards Farc as both narco-terrorists and sworn enemies of the US. The IRA itself has been silent, while Sinn Fein maintains the three men had nothing to do with them. Sinn Fein continues to deny reports that one of the men was its official representative in Cuba.
This week, a senior US diplomat, Richard Haass, who is the Bush administration's leading player on Northern Ireland, has been in Belfast for meetings with various parties including Sinn Fein. He has twice raised the question of Colombia in public comments, and discussed it at his meeting with Gerry Adams, the Sinn Fein president. Mr Adams is said to have raised the issue first at the meeting, acknowledging that Colombia is important for the US but maintaining that Sinn Fein "has no case to answer'' in relation to the three men.
In the days after the Colombian arrests there was speculation that Mr Adams might drop plans to visit Cuba, where he is due to meet President Fidel Castro. Sinn Fein insists, however, that the trip will go ahead later this year.
The Ulster Unionist Party has been lobbying Washington to push republicans hard on the Colombian issue. A party delegation was actually on its way to the United States when this week's attacks took place, causing its flight to be diverted.
The present US administration has given the Northern Ireland peace process a lower priority than did the Clinton administration. In its general approach it has, however, continued to regard Sinn Fein as playing an essentially admirable role in attempting to bring the troubles to a close.
While the Americans have no illusions about the party's close associations with the IRA, their general sense is that the republican movement has been steadily moving away from violence into political activity.
Former president Bill Clinton not only gave Northern Ireland a high priority but also lent huge support to Sinn Fein, in the first instance by dropping the long-standing ban on Mr Adams entering America. He later went on, again in the face of fierce opposition from John Major's government, to allow Sinn Fein to raise funds in America. This is said to have been worth millions of dollars to the republicans. Sinn Fein has been described as the richest party in either part of Ireland.
At the time of the Oklahoma bombing, republicans were relieved that it caused neither the Clinton administration nor the American public to toughen their attitudes towards Sinn Fein or the IRA. This time they will be hoping that American anger and indignation will remain tightly focused on the Middle East rather than extending to produce a backlash against Irish republicanism.
In the meantime, the peace process will certainly be affected by the US crisis during the course of this month, in that Tony Blair is unlikely to be able to devote much time to Northern Ireland in the run-up to the latest political deadline.
The Northern Ireland Assembly must by 22 September re-elect the Ulster Unionist leader, David Trimble, as First Minister if it is not to face a period of suspension or fresh elections. The practicalities are that he will not be reinstated unless some big move on IRA arms decommissioning is forthcoming from republicans.
The American crisis appears to put paid to any notion that Mr Blair could devote a great deal of time to one of the exhausting last-minute rescue missions he has attempted previously.
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