The troubles were an insurgency in the sense you mean though the intensity varied. There were a lot of organisations involved but the simplest way to think about it is as a triangle. On one side were republican paramilitaries of whom the Provisional IRA were the largest and most active, on the opposite side were Loyalist paramilitaries and opposing both (but prioritising the IRA) British State forces namely the British army, and the two main Northern Irish forces, the Ulster Defence Regiment (a part time army reserve) and the Royal Ulster Constabulary (an armed, full time police force). Caught in the middle were the ordinary people who made up most of the casualties.

Essentially the violence erupted out of Protestant resistance to Catholic demands for civil rights and the IRA acted both as a Catholic defensive organisation and a terrorist group trying to force the creation of a United Ireland. They employed several tactics including bombings of civilian and military targets, assassination and ambushes. Their objective was never to control territory but to make the political and economic cost of British control of Northern Ireland too high to bear. In the early years of the Troubles, the PIRA believed that Britain would withdraw after a short but intense campaign. When this proved not to be the case, it moved to the 'long war' strategy of lower level insurgency punctuated by 'spectaculars' such as bombings or assassinations. It's defensive role was not especially successful - communities in IRA areas were far more likely to be targeted by Loyalists than the supposed unprotected. Within communities under y their control, the IRA acted as vigilante police using torture, mutilation and killing to enforce order on their terms.

The British government deployed the Army to Northern Ireland to quell inter communal violence but found itself supporting an unpopular local Unionist government against the IRA. The result was quite over dependence on militarisation in the early 1970s. British troops, especially the parachute regiment, were soon seen by nationalists as their enemies. Three events especially alienated nationalists: the introduction of internment without trial, the imposition of curfews in nationalist areas and the massacre of anti internment protesters in Derry on Bloody Sunday. The Westminster government eventually dissolved the local one and took direct control of Northern Ireland. British strategy was to use force to suppress the IRA while offering reform to the majority of nationalists who opposed violence. The army was considerably more restrained than in, for example, Kenya but still carried out extensive violations of human rights which further damaged its reputation. From 1975, primary responsibility was shifted to local forces (a shift called "Ulsterisation"). This was a response to high casualties in the army.

There was a darker side to British strategy also. The intelligence services were successful in infiltrating paramilitaries on both sides. It is still unclear how much this blended into outright collusion with attacks on those who opposed the state but recent investigations paint a very morally murky picture. Likewise it has long been believed that at least some British forces operated a 'Shoot to kill' policy, especially the SAS. While militarily understandable as the paramilitaries all shot to kill, it was at odds with the official rationale that British forces were acting as a police force. Lastly there was a long standing sense among nationalists that they were all seen as the enemy with a litany of petty harassment, searches and obstructions alienating them.

Loyalist paramilitaries had emerged out of the same violence that produced the IRA and were motivated by a desire to prevent Britain giving in to republican violence by violence of their own. They directly targeted the Catholic population in an effort to punish IRA supporter and provoke sectarian vendetta with the IRA which is what happened. Although they carried out a lot of killing, Loyalists were notably less well organised than the IRA. The best leaders in the Protestant community could fight the IRA by joining the police or army so paramilitaries were often those rejected by these bodies.

In all about 3,500 were killed in the conflict. Republican groups killed about 2,058, Loyalists about 1,027 and British forces about 363. 1841 victims were civilians, 1,114 were British forces, 396 were republican paramilitaries and 179 were Loyalist paramilitaries. (Figures from the Stutton index in CAIN).

The troubles are one of the most studied conflicts in the world and there is a lot of material. The CAIN website (www.cain.ulst.ac.uk) is a great resource with a lot of information.

The best general introduction is McKittrick and McVeigh Making sense of the Troubles.

On the IRA read Richard English, Armed Struggle

On Loyalists, Steve Bruce The Red Hand is somewhat dated but still good.

On Britain, Paul Dixon, The British approach to counter insurgency is an interesting collection.

An excellent sociological analysis of the conflict is Ruane and Todd, *The Dynamics of Conflict in Northern Ireland *

For personal accounts by a civilian try Glenn Patterson, Lapsed Protestant. There are a lot of memoirs by ex paramilitaries but don't trust them too far there are a lot of internal agendas.