Will the lessons of fighting in Ulster help army in the battle for Baghdad?

Although the British Army has spent more than three decades involved in conflict in Northern Ireland, the experience is unlikely to be of great benefit to its men on the streets of Baghdad.

So many differences exist between Iraq and Ireland that surprisingly little read-across will probably be found between the two conflicts. They have different rules, a very different enemy, different weapons and, most of all, different purposes.

The Troubles dragged on for so long that a majority of troops have probably been based in Northern Ireland, some of them undertaking half a dozen or more tours of duty. But war in Belfast and Londonderry was an unusual exercise, not just in its longevity but also in its character. Above all it was a low-level form of conflict, for the most part aimed at containment. By contrast, Baghdad is likely to see sustained and intense conflict.

Two striking and perhaps ominous points stand out. First, although the Army fought against the IRA for all those years, the result in the end was not a clear military victory over terrorism but, in effect, stalemate.

The other ominous feature is that it took the Army a long time – years in fact – to adapt to the facts of military life in Northern Ireland. During that time the security forces suffered substantial casualties.

In the first four years of open conflict, up until the end of 1974, the Army lost 200 men. A further 100 locally recruited soldiers and police were also killed. In the same period the republican death toll, at 160, was just over half that number.

Not until the late 1970s did the authorities put real thought into the question of becoming properly organised. When they did, the death rate dropped considerably, and both sides settled in for a long haul.

The IRA quickly abandoned the large-scale gun battles of the early 1970s, latterly opting, almost without exception, for hit-and-run attacks. The pattern was a gun or bomb attack on patrols and military bases, followed by a swift retreat. The pattern of fighting on Baghdad's streets will be very different to this, given that the Iraqis appear to be planning a mixture of guerrilla activity with conventional warfare.

During the Troubles the IRA used many weapons in a campaign that led to 500 military deaths in total. Its tactics included sniping attacks and bombs of many varieties, such as booby-traps and remotely detonated devices. Using plastic explosives, they developed many types of homemade but lethal mortar shells, rockets and hand grenades.

The IRA never used suicide tactics on the streets, but it invented the tactic of the "human bomb". They forced workers employed by the Army to drive to military checkpoints and then detonated bombs in their vehicles.

In response to this array of weaponry, the soldier's standard weapon was his rifle. Automatic weapons were only occasionally used, often by undercover units such as the SAS. The Army greatly outnumbered the IRA: its problem lay in catching them in the act.

Although it developed many sophisticated items of technology, the Army used no rockets or mortars, no hand grenades or artillery. Armoured vehicles were plentiful, but they were used for patrols or transport rather than as frontline fighting vehicles. No tank battles were fought.

The usual armament for Land Rovers, which were used for the bulk of urban vehicle-patrols, consisted of the familiar sight of two soldiers with rifles protruding from a hole cut in its roof.

Much use was made of helicopters, but their functions were generally confined to transport, surveillance and casualty evacuation. They were not used as gunships, as they have already been in Iraq; nor was there ever any bombing from the air.

In other words, Northern Ireland has been largely an infantry war, shorn of the sort of heavier weaponry that has already been deployed in Iraq. Yet, despite these measures, 160 civilians died at the hands of soldiers, as well as 130 IRA and other paramilitaries.

The fact that active armies inevitably inflict civilian casualties means it is futile to hope that armies can help to win any battle for the people. In Northern Ireland the experience is that troops in close contact with civilians almost always generate friction rather than increase support.

In Northern Ireland there were few stages when the Army or the IRA looked as if they might win; the conflict had the air of a war of slow attrition. While both sides had their successes, it developed into a long-term slugging match and contest of will and endurance rather than a thrust for early outright victory for either side.

While Baghdad will be about conquest, Northern Ireland was mostly about containment, the Army's limited arsenal reflecting the limited objectives laid down by successive governments. Baghdad is going to be very different from Belfast.