"Ireland certainly faces a threat, there is no question about that. The whole threat against the world at the moment is based on US and UK troop movements and so there has to have been a risk attached to allowing US troops through Shannon airport.

"Security at Dublin Airport is good but security can never be good enough. The terrorists keep coming up with ingenius ideas and security has to be as versatile and adaptable as the terrorists. We can't have this Irish mentality of 'we'll be all right'. At the moment we are far too dependent on intelligence units in the US and UK. Our own intelligence unit needs more support. Countries like Britain and the US have "ghter planes whose sole job is to get into the sky within a matter of minutes if an attack is underway . . . we don't have any of those planes.

"There is a massive Muslim population in Ireland and obviously most of them condemn terrorism, but there is a small minority. Our borders are very open and we don't know who is coming into our country.

"Our economy is so reliant on US investment that any incident would be disastrous for us. Incidents like what happened this week will have a big effect on the global economy. It took three years to recover from 9/11. Any incident in Ireland would have a huge impact on our economy."

DR MAURA CONWAY Terrorism expert, DCU school of law and government "Some people have been saying that maybe this threat was made up in order to gain support for what is happening in the Middle East. It is an interesting line of thought but I think in this instance it is wrong. There appears to have been a very serious threat. If you look at the raising of the terror alerts in both the US and UK, together with the increased security at airports, that was done for a reason.

"There have been numerous security measures in place at airports since 9/11 aimed at stopping weapons such as knives and guns getting on board "ights. There appears to be a much greater chance of getting chemicals on board, however.

"We don't yet know to what level the suspects were acting alone, but it does appear as though they had some sort of al-Qaeda af"liation. Airplanes and airports have been favourite targets for terrorist groups going back to the late 1960s and al-Qaeda-af"liated groups are "xated with planes. This plot appears to be highly organised and audacious so it would seem like al-Qaeda is involved at some level.

"There is a debate about whether al-Qaeda was ever a hierarchical organisation. I think that the organisation was tighter in the mid-'90s. After the invasion of Afghanistan, al-Qaeda operatives based there had to scatter and so that has led to it becoming more network-based. AlQaeda is more of an ideology than an organisation. The links between al-Qaeda af"liation groups is weak. It is an ideology that people adopt and then act on."

MICHAEL GALLAGHER Emergency Planning Society (Irish Branch) "Security at Dublin Airport is under constant review and the Airport Authority is satis"ed that it is adequate. There is an issue of striking the balance between maintaining security and not needlessly inconveniencing travellers. I think that what incidents such as what happened over the week highlight is the information de"cit that exists in Ireland.

"Unlike countries such as the UK, there is no single website in Ireland that offers information and updates on emergency situations. The UK Resilience website outlines all departmental updates on issues such as avian "u, heatwaves and terror alerts. Not only do we not have a facility like this but on Thursday there was no information about the terror alert on either the Taoiseach's or the Department of Defence's websites.

"As far back as October 2003 we recommended that a single authority, preferably under the Taoiseach, be established to coordinate the effort in responding to emergency situations. It's not about taking power away from individual departments, it's about having someone to pull it all together."

SHEIKH DR SHAHEED SATARDIEN Chief cleric, Supreme Muslim Council of Ireland "There is a lot of talk that the events that we have seen this week are in fact an attempt by Britain and the United States to cover up for their failings in Iraq and to cover for the Israeli government in Lebanon. That is a strong view that is held by many in the Muslim community in the United Kingdom and here in Ireland.

"That is not a view that I would endorse at all. We in the Muslim community must accept the fact that fundamentalism is taking over our children and turning them into mindless monsters. If we do not accept this to be true we are failing our future generations and that is something we will all regret.

"Irish Muslim leaders are failing our young people who are embracing fundamentalism. It is happening at a remarkable speed before our eyes. . . fascist fanaticism and radicalism is now rife among our young."

"What is happening here is deeply worrying. We are seeing a dramatic change in the attitude and actions of young Muslims here. It is not an overstatement to say that there is an ocean of extremism in Ireland now. Ireland is a haven for fundamentalists. .

"The true crisis in the Irish Muslim community is the failure of guidance from parents and from leaders. There is a power struggle in Ireland now among Imam to determine who are the most powerful leaders of the Muslim community in Ireland and the effects of this is that nobody has had the courage to reject the growing fundamentalism that is spreading through our young people.

"Young Muslims here are being torn between two cultures, drawing them into support for terrorism, anti-Semitism and a hatred of western democracy. It is inevitable that they will be dragged into the training regimes that occur in parts of Pakistan and Afghanistan. This is a horrifying consideration".

PROFESSOR MARC SAGEMAN Academic and former CIA counter-terrorism operative with 10 years' experience in Afghanistan "In the aftermath of 9/11, a lot of the bad guys, let's call them, have totally stayed away from attacking airplanes. They are deterred by security and the perception of security checks being thorough. In the context of the plot in London it is unusual that they were trying to do it at all.

"There is a lot of commentators in the private security sector who talk about such things [liquid-based explosives claimed to have been behind the plot] as being new departures and so on but this is not so at all. In fact, in the early 1990s there was a well-hatched plot to use liquid-based explosives to carry out a similar attack on a range of aircraft.

'That was ultimately cracked when a Japan Airlines plane was damaged and one passenger killed although the pilot managed to land quite heroically. So it is not so new a concept at all. In fact, security personnel are quite aware of all the different methods that terrorists may use but the deployment of speci"c measures is ultimately a political decision, as to what restrictions authorities want to impose upon travellers, given that if it gets too restrictive people will stop travelling.

"You should not underestimate the dif"culty that terrorists have in cracking airport security in so many ways and that is a major deterrent. Airline security is rather hit-and-miss and it is only a part of the overall counter operation. Once the bad guys get to the airport then at that level it is very dif"cult to detect them in some senses but that is only half the story. A major part of the enterprise from the intelligence services' point of view is detecting associations and movements that relate to the planning stage.

"In the context of commentators who talk authoritatively so soon after an event like London [last week's plot], I am very sceptical. I am not sure that it is possible to know anything worth knowing in such a short space of time and they are commenting in a vacuum really. Some of the things that are said are very irresponsible."