A broadcaster best known for his reports from the war zones of the Balkans and on the political upheavals of South Africa, Keane now applies his foreign correspondent's perspective to the bleaker corners of England, Scotland, Wales and Northern Ireland.
In this book, which accompanies the television series, Forgotten Britain, Keane stakes out the badlands of poverty, frustrated ambition, loss of hope and tribal hatreds, selecting a small group of interviewees and letting their lives illustrate the deep-rooted social ills that blight their communities.
There has been a recent spate of books in the "condition of England" tradition which have attempted to take the nation's pulse at a time of transition, but A Stranger's Eye takes a more focused, more precise look at people stuck on the edges.
In Leeds, the author visits a decaying estate, screwed up by drugs, unemployment, poverty and all the crimes that follow in their wake. It's a small world of trashed flats, violence, addiction and broken promises - ending for one of the individuals who form Keane's case studies in an early death through an overdose.
But it isn't an unrelentingly depressing account, because amid the squalor and sadness he finds examples of hope. He visits a community worker who gives young people a breathing space in otherwise tough lives and he meets a young mother determined that her children will rise above the expectations of their surroundings.
Fergal Keane's great strength as a broadcaster and as a writer is his sure sense of touch in dealing with suffering, allowing victims' stories to be heard without appearing to be plundering grief for the sake of a story.
Keane puts this to good use when he interviews a north London pensioner who is too scared to leave his own flat. The account of the elderly widower, who is forced to spend his last savings on a private eye operation to save him from blindness, is a powerfully simple tale of urban misery.
The pensioner's account of a lifetime's hard work followed by a prison-like old age, of the way in which the National Health Service failed his wife when she needed help and is now failing him, is held up as an indictment of what the welfare state did not achieve in the second half of the last century. Perhaps the most depressing aspect of the story is its very ordinariness. And it raises all kinds of questions about how we define poverty, when wht seems to be missing most from such lonely lives is not money but community.
Keane's storytelling is at its strongest when he turns to the town of Castlederg in Northern Ireland, where he tries to interpret the sectarianism that stubbornly refuses to disappear.
Within his portrait of a town burdened by generations of distrust and bigotry, he tells perhaps the saddest and strangest story of all, when he interviews the mother of an Ulster Defence Regiment soldier murdered by the IRA.
The victim, a young man who was a leading light of a Loyalist marching band and who lived alone with his widowed mother, had a closely kept secret: he had been baptised a Catholic, the son of an Irish Catholic father who had met and married his Protestant mother in London.
His mother's story, in post-war Northern Ireland and England, was a cautionary tale of how prejudice will always find a way - ending in the gunning down of her only child on her own doorstep.
Keane is well placed to trace the fault lines in identity between Britain and Ireland, having himself been born in England of Irish parents. After returning to Ireland as a child, he then completed the circle by coming to work in London and settling down to raise his children here.
Questions of identity and the threat to a way of life are at the heart of his journeys to Scotland and Wales - whether it be shipyard workers in Govan fearing closure or hill farmers in north Wales facing bankruptcy. In both cases, the fear is as much for the future of a whole community with its own history and traditions as for the loss of livelihood.
In all these travels, Keane presents the voices of the disenfranchised, the underclass who are often talked about but rarely get a chance to be heard. He writes with great compassion and interweaves his own experiences of poverty and exclusion with the descriptions of his subjects, in a determined effort not to sound as though he is writing from above.
If A Stranger's Eye had been a foreign correspondent's only despatch from the UK, it would have presented an engaging but narrow glimpse of the country. And perhaps, while extremes of poverty have a certain journalistic clarity, it might have made for a more challenging work to try to show something of the mainstream from which these people are excluded. The new middle class is in many ways even more of an unknown country than the more graphic suffering of the poor.
But that would have been another book and, within its own terms of reference, A Stranger's Eye succeeds in bringing dignity to the struggles of communities and individuals who have usually been afforded little respect.