IT HAD NOT OCCURRED TO me before I read this book that perhaps the only losers from the making of peace in Northern Ireland were the mobile phone companies.

The long and winding path to the end of the Troubles, which lasted almost 40 years and killed 3,500 people, went via thousands of phone calls. Conference calls invaded the lives of the principals for years on end as the IRA inched slowly towards admitting that it was not going to kill anyone any more.

Jonathan Powell, Tony Blair's chief of staff and Irish negotiator, bicycled through the Suffolk marshes listening to his mobile loudspeaker relay a conversation between Blair and Ian Paisley Jr. After one particularly long phone call between Blair and Gerry Adams one Christmas Eve, the senior civil servant who had also been on the line could not be contacted. His exasperated wife had finally hidden her husband's phone in her own search for peace.

A negotiating process fascinates those involved while it is happening; reheating the cold details when the outcome is known makes for a stiff literary challenge. Large chunks of this book can be summarised roughly like this. Powell writes Tony a note; Tony agrees or amends. Many phone calls are made; secret meetings are held and notes exchanged. Not-so-secret meetings are held and optimism rises. Then someone changes tack or walks out. Pessimism mounts. Every few years, all the parties meet in a very grand building somewhere with terrible weather. In the last chapter the most unlikely couple, Martin McGuinness, of Sinn Fein, and the Rev Ian Paisley, fall exhausted into each other's arms. Peace breaks out.

We should be grateful that it did. This book makes plain that Blair and Powell deserve credit for truly unusual commitment and energy. They believed in talking and never stopped for ten years. This is the best-informed rough draft of history so far written by someone who was on the roller-coaster ride to a settlement.

What Powell's book doesn't do is to explain causes and effects behind events. Blair and Powell inherited a promising ceasefire from the equally dedicated John Major. Once Blair had briskly ditched his party's republican-flavoured Irish policy, he built on Major's foundations. Rival organisations killed people, too, but events have proved that when the IRA stops, so does everyone else.

Enough evidence has now emerged to suggest that by the late 1980s the IRA had been so throrougly penetrated by British intelligence agencies that it had been gradually, but fatally, weakened. That handed the initiative to men such as Adams and McGuinness, who had realised that politics was all that they had left. This contrasting pair then concentrated their efforts on delaying the final settlement until they had extracted the best price they could for their concessions and lowered the expectations of the gunmen. That took them 15 years. No one in the entire cast of the search-for-peace drama ever said that the IRA “surrendered” or had been “defeated”.

Powell sticks rigidly to this reticence. New Labour has taught us all that to be convincing, you must have a compelling “narrative”. Wanting to keep the narrative on civilian peacemaking which was, he implies, superior to what had gone before, questions go unasked. A perfunctory epilogue does not separate individual contributions from broader forces at work.

Intelligence agencies make implausibly few appearances in his story, and then only to help with talks. Powell barely addresses the question of why an armed conspiracy dedicated to achieving British withdrawal and a united Ireland by force should settle for elected office with limited powers in a still-divided island.

Both halves of Ireland changed during the Troubles: the south grew affluent while the north was reconnected to Britain and its subsidies. Both shifts worked against political violence. September 11, 2001 terminated American indulgence of republicanism. Any lingering sympathy across the Atlantic then evaporated when an IRA trio were caught weapon-shopping in Colombia. Simple weariness played a part in winding down the shooting and bombing: the glamour of “physical force” had worn off.

By the end of the book, the reader will think it a pity that Powell did not prune the negotiating record in favour of more reflection and diversion of his own. He drops in a few jaw-dropping disclosures but always returns too soon to shuttle diplomacy. On two occasions Powell drafts a segment of a speech for Adams and is astonished to hear it spoken as he wrote it. McGuinness casually tells him that the years and millions of pounds spent on the Bloody Sunday inquiry weren't needed: an apology would have done.

Least of all does the author seem at all curious about the implications of his own role. The ministers nominally in charge of Northern Ireland ranged from the obedient (Paul Murphy), through the pompous (Peter Mandelson) to the idiotic (Mo Mowlem). But they were all out of the loop. Powell reported to Blair and to the Prime Minister only. Blair's confidence in his own persuasive skills (his “Jesus complex” in Mowlem's phrase) wasn't misplaced, but this was presidential policymaking in all but name. Another policy made in that way in the Blair era gets fleeting mention. Iraq doesn't even have an entry in the index.

Great Hatred, Little Room: Making Peace in Northern Ireland by Jonathan Powell
Bodley Head, £20; 352pp

Extract

The ensuing negotiations were extremely complex. Tony had to leave for an official visit to Japan so he charged me with sorting the matter out. This involved managing an elaborate three-way discussion between the Irish, Trimble and Tony in Tokyo while taking account of the various time zones. Once Trimble had seen the Irish draft he rejected it out of hand and we had to abandon it and start again with the original British draft with a few Irish amendments that Tony and John Holmes drew up in Tokyo.

On Saturday, January 10, I recorded in my diary that I had to make more than a hundred phone calls during the course of the day, the last one at half past midnight with the news that Trimble had briefed The Sunday Telegraph with his account of the negotiations. All the other parties, not surprisingly, got into a state at being excluded. I got Tony to call Mo from Japan first thing in the morning on Sunday, even though he had been kept up till after three by the negotiations. At first she hadn't seen the story and was relaxed but once she did, she got into a terrible rage, putting the phone down on Tony once and then accusing us in No10 of undermining the whole peace process by leaving out the smaller parties...

As Mo said in her autobiography, she attached great importance to inclusiveness, wanting all the Northern Ireland parties, even the tiniest ones such as the Women's Coalition, to participate fully in every step of every negotiation as well as the big parties. While an admirable goal, it was not practical politics. It is not possible to make progress in a sensitive negotiation if you require parties to make compromises and reveal their true positions in public. Neither side will move.

So I went back to my telephone diplomacy, and after a Sunday on the phone from 7.30am to midnight, I finally had an agreed text, having persuaded the Irish to retreat on the issue of North/South executive agencies.

Times Recommends

• The Sunday Times 100 best holiday reads
• What will we be reading this summer: the booksellers predict
• Literary festivals: a survivor’s guide