APART from providing protection for visiting dignitaries, particularly British VIPs under threat from the IRA, the Army Ranger Wing has only once been deployed as a unit in its 19-year history.

In January 1997 two teams of about 12 Rangers were sent to Mountjoy Prison where three prisoners armed with knives had barricaded themselves in the Medical Unit and were threatening to kill two prison officers.

While they took up position ready to blow down the steel door to the unit and probably kill the hostage-takers, negotiations resumed.

The Rangers have honed their hostage-freeing skills to the point where they can burst into virtually any location and neutralise the threat to the hostages (that is, kill the hostage-takers) in a few seconds, even in pitch darkness.

The Mountjoy siege ended within a few hours of the Rangers being called in. It is not admitted officially that their presence had an effect in ending the siege but it may have sharpened the hostage-takers' thinking. They faced two clear options: surrender or be killed.

Within the Defence Forces, the Ranger Wing is the unit that is most obviously defined as a killing machine. Its members learn to use a variety of lethal weapons with precision and speed. Its relatively low profile may change now that it is being deployed for the first time in strength in a dangerous, foreign environment.

The departure tomorrow of its reconnaissance team of eight soldiers is also a point of change for the role of the Defence Forces in UN missions.

The Defence Forces' mission statement, issued in September 1993, defined their role as defending the State against armed aggression; aiding the civil power (i.e. the Garda); and a number of non-military matters such as providing fishery protection, search-and-rescue, air ambulance and ministerial air transport, as well as helping in emergencies or in the event of disasters. The unit is also mandated to "participate in United Nations missions in the cause of international peace".

It is under this last condition the Government has decided to send a unit of Rangers to East Timor.

It is the first time that Rangers have been sent abroad as a unit. It is also the first time that the Defence Forces have deployed troops on a UN mission whose role cannot be strictly defined as a "peacekeeping" or logistical support one. The UN mission in East Timor is now a peace enforcement role.

The UN enforcement missions are known as Chapter Seven missions because their definition is set out in that chapter of the UN Charter. Peacekeeping missions are defined in Chapter Six.

The Dail will have to pass an amendment to the Defence Act to allow the unit to participate in the East Timor mission. A similar amendment was needed to allow the Irish transport unit to participate in Somalia in 1992, another Chapter Seven mission.

But the transport unit in Somalia had a clear humanitarian element in its role, collecting and transporting provisions for the Indian brigade stations in the famine-hit interior while the Indians rebuilt wells and repaired what infrastructure was left after years of civil war.

The Ranger Wing's role in East Timor is not yet defined. The reconnaissance group will liaise with the office of the Australian Force Commander, Maj Gen Peter Cosgrove, about the deployment of the wing. The Australian army has its own specialist troops, known as Special Air Services, and there is said to be very considerable interest among the Australian military in the unit coming from Ireland.

There is, similarly, considerable interest among the Defence Forces here in the likely role of the ARW in East Timor.

According to Army sources its most likely role will be in protecting other UN personnel as the UN mission re-establishes itself in the wake of the withdrawal of the Indonesian army undercover troops who have been supporting the local militias.

THE Rangers are ideally suited for this type of mission. They will need to operate in difficult, hostile terrain - something they train to do. Their other skills of intelligence-gathering, concealment, communications, sniping and their extreme fitness are all assets that may make them invaluable troops in such a hostile environment.

Despite the fact that Rangers are highly trained killers, Army sources insist they will not have a Rambo function, stalking and killing enemy soldiers.

In effect, they will be carrying out the role they are most commonly called on to provide at home, VIP protection. The Rangers are present for every visit by a major dignitary. They provide support for the Garda's Emergency Response Unit (ERU) with snipers positioned at points around the sites where the VIPS are in public view. There are inevitably members of the ARW in civilian attire providing "close protection" around the VIPs.

If there is a sustained withdrawal of Indonesian forces and the militias also withdraw from East Timor, and allow the return of refugees, the Australian-led force may face a relatively easy task in restoring peace. If there is continued conflict and Indonesian forces return, then the Rangers and all the other members of the force could find themselves in highly dangerous situations that will require the use of lethal force.