Derry is different from Belfast. Excuse this apparently trite opening remark but it’s relevant, since both these books have Derry authors. Read together, they just might push the ill-informed to the realisation that the Troubles aren’t just a bloody joust between two immutable and monolithic communities.

A standard London and Dublin response is to throw up one’s hands in derision and despair and claim little has changed in the North’s two entrenched positions. And yet any sane examination must lead to the conclusion that the context has shifted through the impact of the European Community, the differing fortunes of both the British and Irish states since 1968 and, finally, the immense changes in the global economy over the past 25 years.

Furthermore – and it’s a fault of Southern coverage that should be blamed on disinterest rather than Section 31 – we can be blind to the changes within both communities. To understand how and why Derry is different from Belfast helps to define both the opportunities for and the obstacles to peaceful change.

In 1968 and through the early Seventies, as both Eamonn McCann and Shane O’Doherty record, Derry was the cockpit of the militants while Belfast was the haven of the moderates within the Nationalist community. Yet now, 25 years on, positions are reversed. It is Derry’s Sinn Fein that gropes its way to political sophistication while the Hume/Adams initiative is disabled by the reckless Shankhill attack of the Belfast I.R.A.

I know this is a simplification, and that the reasons for this reversal can also be simplified. But it is true nonetheless, I believe, that Derry Nationalists were militant because they could win and are now moderate because they did. Belfast Nationalists were moderate because they could lose and are now militant because they did.

Derry was more militant because it was the scene of the most glaring discrimination in the Unionist gerrymander of the city’s Corporation. But as Eamonn McCann also documents, the Derry Nationalists could march and riot to make the town ungovernable until they were in a position to insist that the local government of Derry would be changed in their interests – an achievement which, however limited, gave them some sense of security and empowerment. But such options were never open to the isolated, outnumbered Nationalists of Belfast, who would always be outgunned.

Again, one can observe the changes in the representation of the two cities. While Derry had elected traditional Nationalists like Eddie McAteer, Belfast’s original leadership went to Labour politicians like Gerry Fitt and Paddy Devlin who, at the least, had to give the appearance of care for non-sectarianism and cross-community politics. And yet the Fitt/Devlin generation was swept overboard by Sinn Fein in the wake of the hunger strikes. Was it purely due to the tidal wave of emotion engendered by Bobby Sands and his dead colleagues?

I believe not. Nor do I believe it was only due to the improving organisation of Gerry Adams’ Sinn Fein or the sense of fear and powerlessness in Belfast’s Nationalist ghettos before the security forces – though obviously both were highly significant. There may be yet another factor – the worsening economic position of those same Catholics.

This leads to one of the key perceptions of War And An Irish Town. Faster than most in the Civil Rights Movement, Eamonn McCann and his colleagues learned the same lesson as urban blacks after the death of Martin Luther King, namely – you can’t eat Civil Rights.

It’s long been conventional wisdom to point to protection rackets and blame the economic miseries of places like Ballymurphy on the I.R.A. And obviously Ballymurphy is far from the first place any entrepreneur, however generously subsidised, would site a brave new venture.

But that analysis is insufficient. The tragedy of the North but especially of Belfast is that the Troubles overlapped with changes in the world economy few could have predicted in the relatively prosperous climate of the Sixties. Even in the most peaceful, benign environment imaginable, employment in Belfast was doomed to be savaged, with Catholics inevitably being the worst victims.

But as Eamonn McCann also points out in his lengthy introduction to this new edition, the Protestant workforce wasn’t immune either. The Harland and Woolf shipyards, which once employed over 30,000, now has 2,500 workers. You can argue that Hume/Adams has been the political catalyst for the recent U.F.F. viciousness but a deeper source of this barbarism may be the realisation among Loyalist paramilitaries that a job is no longer their birthright.

And they still believe it’s the Taigs’ fault. Thus the central tragedy of the Troubles – while the middle-classes of this island proceed, however erratically and falteringly towards the 21st century, the workers and unemployed of the North are effectively barricaded amid the debris of redundant Nationalist and Unionist ideologies from the first half of the 20th.

Or while the spectres of Orange and Green squabbled over the declining proceeds of the industrial welfare system, capitalism changed the game behind their quarrelling, inattentive backs.

Dublin is different from Belfast too but not necessarily in the way that Nationalists and Unionists have respectively mythologized and vilified the Southern state. Indeed Eamonn’s introduction begins from that point, at the division between the South and Northern Nationalists after the Warrington bombings. As he states: “All recent attempts by Northern nationalists to guilt-trip Southerners into a serious, active commitment to the anti-partition cause have failed.”

Yet as he further argues the cooling of the South’s ardour for a united Ireland isn’t merely due to revulsion at I.R.A. violence. Instead Southerners recognise the obvious; that their own problems wouldn’t “be alleviated if all the British soldiers in the North were to take to the troop ships and head home in the morning.”

Of course, you could have said the same in ’68. But Eamonn goes a step further, questioning Unionist myths about Southern society, and arguing that events like the election of Mary Robinson and the furore over the X Case indicate Home Rule is ceasing to be Rome Rule.

Such changes should compel a Unionist rethink but their leadership seems politically paralysed, blind to the fact that the old Imperialist alliance has been frayed if not yet quite torn apart.

Personally, I accept the political fact of the Unionist right to self-determination; I merely dispute whether it will be exercised prudently. For Unionists don’t seem to realise how Europe has replaced the British Empire as the context. Likewise, they don’t seem to understand how Margaret Thatcher eroded the Union as much (if not more) through her economic policies as through the Anglo-Irish Agreement.

Economically, Unionism did make overwhelming sense from 1886 through till the 1980s and it still makes sense in terms of a shared heritage and such matters as the superior health and welfare services of the British state. But there may now be larger historical forces, distinct from Irish Nationalism, serving to undermine the identity of self-interest between Ulster Unionism and the United Kingdom.

Margaret Thatcher and John Major might pose as righteous Tory nationalists, British Firsters opposed to European federalism but their economic policies dismantled the Imperial industrial system that made Belfast a sister city to Liverpool and Glasgow. And despite all their anti-European rhetoric and posturing, the new businesses and the new investment poured into the Tory heartlands of the South of England, closest to the Continent.

James Molyneaux’s parliamentary pas de deux with Major may buy the Unionists some time but he doesn’t seem capable of withstanding the undisciplined market forces that could contribute to the economic peripheralisation of Northern Ireland within the United Kingdom. And even if my argument is overstated, it still makes sense for Unionists to abandon their Imperial myths and regalia and consider popping into the political bookie’s shop and laying off on their wager on Westminster.

At 62 pages, Eamonn McCann's preface can't entertain all these ideas or explore them all the way. As he himself accepts, he leaves a lot out – but there is certainly enough in here to fuel speculation and debate about all the misunderstandings and missed connections in Northern politics.

He also moves seamlessly from the specific to the general; from anecdote to insight. Elucidating the tragedy of the slain sex abuser, "Jim Harkness" and the farce of the dope-smoking Sinn Fein councillor, Hugh Brady, he reveals both the internal stresses of Derry and the heavy-father authoritarianism of Sinn Fein itself.

Twenty years on, he admits to partial dissatisfaction with the original text, conceding that “some of the predictions now seem naive, some of the judgments wrong-headed, some of the language inappropriate.” And the question which lurks within its pages without ever being fully posed is whether the drive for Civil Rights could have progressed without so severely alienating Protestant workers.

Probably not. As he suggests, they had mortgaged both their financial welfare and their consciousness to the Unionist system. And if there was a very vague chance that they might have been reconciled by a full-blooded Socialist campaign, the all-class Civil Rights alliance was not equipped to unfurl any Red Flags.

So the Protestant workers of the Waterside are notably absent from the bulk of War And An Irish Town, sidelined in the increasingly violent struggle between the Bogside and the forces of the Unionist and, later, the British State. Thus the central tension of the book is between his non-sectarian socialist ideals and his even stronger experience that the Croppies couldn't, wouldn't and shouldn't lie down.

At his best, his writing embodies all these tensions at their most chaotic. A discussion of the shooting of Ranger Best by the Official I.R.A. is interrupted by a choicely comic paragraph about Fr. Hugh O'Neill, administrator of St. Eugene's Cathedral who accuses McCann of being the Devil, Satan himself in human form, before shifting his suspicions to the local Korean community which "resulted in a confrontation between a Daily Express reporter and a waiter from the Rice Bowl restaurant from which the waiter, quite possibly, has not yet recovered."

Sometimes you must laugh before you cry. It is not necessarily unfeeling but instead strangely sincere in a way that outsiders can only imagine, to sometimes use such a foreground of comic mania to innoculate against the background of tragedy.

But his sensitivity to the Bogside community also means he understands "the hooligans” – the teenage stone-throwers and petrol-bombers who graduated as the Provisional I.R.A.'s prime recruits. And, of course, this is where Shane O'Doherty enters the story.

It's difficult to know how representative Shane O'Doherty was and is. A volunteer at 15, a prized operative sending letter-bombs to Downing Street at 18, O'Doherty was arrested and imprisoned at 20, an age when most students are still debating the respective merits of The Smiths and The Cure.

Moreover, he doesn't quite match the political photofit of McCann's hooligans. His family were sufficiently better off to make a difference in Derry. Reared on a mixed street, he played with Protestant children and writes that he even had a Protestant girl-friend – though she didn't know his secret – while he was an I.R.A. member.

Again there are bizarre elements. His cousin and two of his elder brothers had served with the British forces and at 15, Shane O'Doherty resourcefully marches down to the Bogside front-line, wearing a British Army gas-mask to protect himself against the CS.

But he was a romantic, in precocious awe of the leaders of the 1916 Rising even before Derry exploded in ’68. The early riots and the pig-headed brutality of the R.U.C. – Eamonn McCann insists the defenders of law and disorder once unsheathed their batons singing "Hey, hey we're the Monkees/ And we're going to monkey around/ Till we see your blood flowing/All around the ground" – made his decision inevitable.

And yet his commitment wavered. A rocket attack on a British army post misfired and the army shot and wounded a woman and her two children. Riven with guilt, he retired from the fray until the politics of the last atrocity produced another sadistic twist and the horrors of Bloody Sunday returned him to the I.R.A fold.

But at 18 he was still a political innocent. O'Doherty makes great play of the comparative restraint and discipline of the Derry brigade and how it concentrated on economic targets not civilian killings. As he concedes in The Volunteer, he had scant conception of the sectarian bitterness that bedevilled the I.R.A. in Belfast and in many rural areas of Northern Ireland.

So, at the time, he justified the London letter-bombs as a publicity-seeking exercise. Even now letter-bombs or small doses of gelignite scattered in Oxford Street wastebins produce headlines that far larger explosions in Northern Ireland don't, a political fact that emphasises the confusion and muddle-headedness of the mainland's commitment to the Union.

It was also an ideally simple and economic operation, one volunteer with his stash of gelignite alone against the Crown. But on his return to Ireland, the I.R.A. would get more ruthless, stupid and literally bloody-minded with the murder of 21 civilians in the Birmingham pub bombings.

Yet again, O'Doherty's own conscience was afflicted. He also cheerlessly realised he was personally trapped, with "no sense of an existence independent of the I.R.A., primarily because I had given my life to it, was on the run from police and army, was going nowhere except to the graveyard or to prison, and had no way out except by a cease-fire and a related deal or amnesty."

"The discovery that I had sold my soul to the organisation was repellent to me," he writes. He began to crave a normal life and, six months later, was arrested at his family home. One might start to suspect he unconsciously wanted to be caught.

If I pass over his 14 years in prison, it's sadly because tales of ignorant brutality by prison warders no longer surprise. For while Shane O'Doherty gradually recanted his I.R.A. past, he refused to accept the prison regime, both individually and in its brutalisation of other long-term prisoners.

But what does The Volunteer explain about the I.R.A.? That's difficult to estimate since O'Doherty writes with an understandable reticence about operational secrets and individuals' identities. Also he can present himself as an efficient, young idealist, disabused by blundering senior officers whose incompetence can lead to deadly accidents.

Obviously they may consider this special pleading yet it sometimes helps to see the I.R.A. more as fools than knaves. In 1974, during the last chance of a cease-fire, the I.R.A. mount a Big Push to prove their political virility but instead needlessly lose volunteers and pollute the stream of peace. One need not be a clairvoyant to see parallels in the minds of those who planned the disastrous Shankhill bombing.

Again Derry is different from Belfast since Shane O'Doherty claims he believed in a cleaner, purer Republicanism that wouldn't surrender to sectarian bloodlust. Barely 18 when the British army opened fire on Bloody Sunday, he just couldn't conceive how the I.R.A.'s campaign would become the greatest impediment between the Shankhill and the Falls.

Nor might a teenager appreciate the bloody consequences when violence becomes the first language of politics. Or as Eamonn McCann conceded in his discussion of "Jim Harkness" and his sexually abused victims: "The idea of responding with direct, extreme violence against anyone perceived as threatening the community has come to seem to many the natural way of doing thing, a first option rather than a last resort."

The answer is politics. Not the politics of traditional Unionism and Nationalism but instead a politics that recognises the changes within both communities. For Unionists, especially working-class Unionists, it means acknowledging that the crisis in the Union is not solely caused by the I.R.A. or any supposedly pan-nationalist pressures. They still have the right to resist conscription into any Southern state, especially one with enduring Catholic characteristics, but they might very usefully start to inquire whether their self-interests are best served by exclusively organising in terms of the British State.

They might also usefully abandon their sectarian stereotypes and investigate the changes within the Nationalist community. But not only in terms of the South, since outside of Eamonn McCann's introduction, it is rarely stated that the most obvious beneficiaries of the last 25 years have been the Catholic professional and middle-classes, whose grandchildren in Queen's now have opportunities their grandparents wouldn't have bothered dreaming about under the Stormont system of discrimination.

But you can both recognise that fact and imagine its potential consequences in Derry. Less so in Belfast, where the political result of the H-Blocks hunger strikes was to create a divided city council with a chasm between Sinn Fein and Loyalist local politicians. And while the I.R.A. continues its military campaign against the wrong enemies, Unionists will never lose their blindfolds.

There can be no politics without peace.

War and An Irish Town by Eamonn McCann is published by Pluto Press at St£9.95

The Volunteer by Shane Paul O'Doherty is published by Fount at St£4.99