There was one final person without whom we may not have won: Silvio Berlusconi. The previous August I had gone to visit him at his home in Sardinia to seek his help with the bid. Italy was a key player. He asked me how much it mattered to get the Olympics. 'It matters,' I said.

'Greatly?' he asked.

'Greatly,' I said.

He said, 'You are my friend. I promise nothing but I see if I can help.' Typical Silvio, which is why I like him. Most politicians say 'I promise' but then do nothing. He said 'I promise nothing' but then delivered.

Personal relationships matter this is obvious, of course, but is also completely ignored by people who think it's florid stratagems and mathematical calculations that drive negotiations and compromise. At all levels, but especially at the top, politics is about people. If you like a leader, you try to help them, even if it stretches your own interests. If you don't, you don't. And if you distance yourself on political grounds for example because, like Silvio, there's controversy around them then fine, but don't kid yourself: your own country's the loser. That leader is not a fool, and knows you are not prepared to pay a price to have a relationship. You think they don't harbour a grudge about it? I have no idea how the Italians voted, but ...

We left Singapore not daring to hope and yet still hoping, which I put down to the exhilaration of it all and the fact that people are always nice to your face. But somehow it didn't feel like a done deal for France any more.

We landed at Edinburgh airport after flying overnight, and drove up to the grand Gleneagles hotel. I'd chosen Gleneagles not because it was grand, but because we needed somewhere that could be secured. The 1998 G8 in Birmingham my first had been right in the city centre, but the world of summitry had changed in the seven years since then, even before September 11 and certainly after it. We live in an era of publicity through protest. Because the modern media works essentially through impact, protesters know that if they protest in a sufficiently disruptive way, they lift the agenda from the democratically elected politicians. Hordes can descend on a summit and wreck it, dominate the news coverage, diminish its salience; in short, devalue it. In turn, this forces politicians to try to insulate themselves from the protest, and after the Genoa summit in 2001 they tended to be held in faraway or remote places not so susceptible to disruption: Evian in France, Heiligendamm in Germany and Sea Island in the US.

As we drove into Gleneagles we could hear the shouts of the anti-globalisation protesters who were against us meeting, who were against the G8, who were against the whole system. My thoughts towards them were not charitable. Why shouldn't we meet and talk? After all, it is about Africa and climate change. What is your problem? In other words, I felt about them roughly what they felt about me.

I then had to meet Jack McConnell, the Scottish First Minister. It was important for him to be seen as part of the 'happening' as the security arrangements had all been really tough to carry out. He had had to meet local residents, sort out the policing of the huge pre-G8 rally held a few days before in Edinburgh and, as usual, everyone wanted the G8 but at the same time wanted to complain about the disruption.

Amazingly I had slept on the way back from Singapore, thanks in part to my pill. Once I had bathed and sorted myself out I felt fine, except of course for the sick feeling waiting for the Olympic result. Clearly there was nothing else I could do about that now, so I concentrated on the G8.

I had decided to do it differently this year. I was in a weaker position internally following the election. Gordon and his folk were agitating. The media were kicking my backside more or less incessantly. I had been forced into talking about the transition to a new leader when doing so was both a little humiliating and weakening.

By then, however, I had reached a new stage of development within myself. I was not happy the pressure was really tough but I was mentally very strong. I would give it two years minimum. That was at least the most consistent I could be with my pledge to serve a full term not a fulfilment of it, obviously, but not so flagrant a breach as to be a real betrayal of trust. If Gordon and I had been working in tandem on an agreed agenda, I might have gone before that, as I have said; but on the a.s.sumption it was still difficult, I would continue at least two years.

If those in the party or the media were to go for me and get me out forcibly before then, there would be a bloodbath. And prior to that point, I was going to do what I thought was right. I had been operating on that principle for the past few years and it was going to continue like that. I wasn't going to back down. Simple as that. I was going to take the risks of failure rather than let fear of failure diminish the scale of ambition. And I wasn't going to waste a moment or set my sights low. Hence the different G8 agenda.

Usually, the G8 focused on the issue of the day and, traditionally, was always about the world economy. Its membership represented historical rather than present economic and political power. Gradually we started to involve others informally, something we began at the G8 in Birmingham in 1998.

This time I took it on to a whole new level. First, I invited five nations China, India, Brazil, South Africa and Mexico for more or less the whole summit, supplemented by various African and Arab leaders. G8+5 became a new format that enabled the largest global players or most of them to gather, albeit informally, at the only non-regional global political meeting outside a formal UN or WTO structure.

Second, I decided to go for an ambitious set of outcomes. I defined the objectives as twofold: get a comprehensive package of support and partnership agreed for Africa; and at least establish the principle of a new global deal on climate change to include the US and China to follow the expiration of the Kyoto Protocol in 2012. The Africa package was based on the Commission for Africa that I had set up back in 2004 at the instigation of Bob Geldof.

Bob. What can I say about Bob? He can drive you completely nuts. He can talk forever. He can speak to world leaders like they were errant schoolkids. Personally I didn't mind that but I was the exception, believe me. Bob can be rather unreasonable in his persistence, actually manic about it. However, he has two enormous saving graces: he is smart, and he is brave. He is smart enough to know when to stop short of provoking catastrophe or making an unreasonable demand non-negotiable. He is brave because he isn't one of your fair-weather, 'don't sully me with compromise', 'now you're not popular I don't want to a.s.sociate with you' types of which the arts world is inordinately full. He and Bono are both genuinely committed, properly knowledgeable and ultimately care more about getting things done than about protecting their egos.

The Africa Commission was staffed by high-quality people. The make-up was balanced but serious, the African members in particular being savvy, clear-minded and determined to demonstrate the central thesis of the report: in the end Africa should sort out Africa. They were in the cla.s.sic 'hand up, not handout' mode. Yes, we needed increased aid, but the purpose was to help get Africa on its own feet, with no rubbish about not being able to govern because of the wicked colonial past. My view on Africa had always been essential third-way stuff: we need a partnership between the developed and undeveloped world, not a donorrecipient relationship. Governance and corruption were as big a problem as debt and aid. Conflict resolution was central. In other words, the hard and the soft. Though the Western citizen felt genuinely sorry for the plight of the Africans, they had also somewhat come to fear it was a hopeless situation. Giving money was a moral imperative, but there was little real belief in it delivering the outcome, which in turn led to 'donor fatigue'. This was something Bob and Bono knew instinctively, and if they hadn't, their first meeting with George Bush would have put them right.

I knew Bono would be an important person to get to see George. Bono could have been a president or prime minister standing on his head. He had an absolutely natural gift for politicking, was great with people, very smart and an inspirational speaker. I spent a long time wondering what made him so good at what he did. I finally decided that, apart from hard work, he had that characteristic I saw in every truly successful person I ever met: he is motivated by an abundant desire to carry on improving, never really content or relaxed. In the right way and under control, that motivation also imparts a certain humility. I knew he would work George well, and with none of the prissy disdain of most of his ilk.

George was, truth be told, anxious about my G8 agenda. He never loved summits, even in fact distrusted them. He felt their pressure, disliked the inevitable focus on America 'not doing enough' and resented the hypocrisy that marked and occasionally defined them. I had to use a lot of my capital with him which was nonetheless considerable to get him to agree the agenda and go with it.

He was very tough on Africa and governance, rightly, and he had after all doubled aid to Africa, and was sceptical about climate change. George is a real conservative, and has the qualities I admire in conservatives and also those, politically, that make me not one myself. One of these qualities is that if a great public lather is whipped up over something, the first instinct of conservatives is to resist it and they are often right to do so. They don't come to a viewpoint because everyone tells them they should.

This att.i.tude is the reason that while people might say they don't like conservative politicians, they still vote for them. People tend to go with the crowd; but in an odd sort of way, they respect a leader who is prepared to defy the crowd. Indeed, if he or she is not prepared to do so, the public suspect he or she is not a proper leader. It's weird the way it works, but there it is. Progressive politicians often don't get this. They prefer to be with the tide of thinking, and get confused when the public say in an opinion poll that they believe X, only to vote Y at the ballot box.

I always remember in the 1983 election fighting on the then Labour policy of withdrawal from the European Economic Community. I didn't support it myself and had told my selection committee as much; but out on the campaign trail as a new candidate, trying to keep my nose clean, I stood on the party platform. The opinion polls showed big majorities in favour of withdrawal, especially among Labour supporters. In a strong Labour seat, it should have been a sure-fire vote winner. It wasn't. Much to my consternation, I was advocating a policy that not only was one I did not believe in, but neither did my natural supporters. In the end they accepted the Conservative argument that it was just not practical to get out of Europe. Interestingly, the party positions later reversed; but the public reaction was the same. No party in Britain will win an outright majority on an anti-EU platform today unless the public go daft, and by and large they don't.

Anyway, that is to digress. The point is that when all the world says climate change threatens the planet, the natural reaction for people like George is to reply: 'So you say, but I'm not convinced.' The more strident the claim, the more resistant they become.

At the Genoa G8 in 2001 his first we had a discussion on climate change. The Belgians at that time had the EU presidency, and so they were also at the G8 table. The then Belgian prime minister, Guy Verhofstadt, is a nice guy and bright, but very Brussels. Kyoto had been agreed and Bill Clinton had signed it, but the US Senate had voted 980 against ratification. On a.s.suming office, George had flatly dissed the whole thing. Later, I think he knew he had made a tactical error. The truth is that whatever he said, at that moment and in those circ.u.mstances there was no way Congress was going to pa.s.s it. He could have taken a low-key position. Instead, as is his wont, he said what he thought, which was that he wasn't convinced, either by Kyoto or actually by the basic argument about the changing of the climate. He added that there was no way America could possibly meet the Kyoto targets without doing immense damage to its economy, and he was just not going to do that.

After George had finished, Guy said he understood what George was saying, but really the American problem had a very simple solution, one that would be good for the world, but also immensely beneficial for the inner well-being of the American people: they could cut their emissions significantly if they doubled gasoline prices by raising the taxes on it. Such an action would be bold, it would help wean the American people off their obsession with the motor car, and earn George the high approval of international political opinion, not least in Belgium.

George had arrived bang on time for this first discussion and had not fully said h.e.l.lo to all the partic.i.p.ants. He didn't know or recognise Guy, whose advice he listened to with considerable astonishment.

He then turned to me and whispered, 'Who is this guy?'

'He is the prime minister of Belgium,' I said.

'Belgium?' George said, clearly aghast at the possible full extent of his stupidity. 'Belgium is not part of the G8.'

'No,' I said, 'but he is here as the president of Europe.'

'You got the Belgians running Europe?' He shook his head, now aghast at our stupidity.

So to describe George as a sceptic on climate change would be an understatement. As time progressed he shifted his thinking, but did so too slowly a quality of conservatives I don't admire and as much because he could see American dependence on carbon was putting their future into the hands of unstable and treacherous parts of the world. Once he had moved, he spent more on developing clean fuel than any previous administration. Actually, he also trebled aid to Africa. But as ever, because the world had come to have a fixed view of him, he got no credit.

I once asked one of my backbench MPs why he hated George so much. This had been one of those embarra.s.sing occasions that even cropped up with some of my close friends, who would ask in private what I really thought of George Bush. I would say I really liked him. It never failed to produce complete incomprehension. When I asked my backbencher why he hated him so much, he said, 'Just do. Can't explain it fully, but just do.' I then asked if it would make any difference if he turned out to be right. 'In that case I think I would hate him even more,' he replied.

So that was how it was with George. He had moved some way by the time of the July 2005 G8, but not as far as I wanted. He had constantly refused to say he would commit the US to being part of a deal on climate change. And although he had been really forward on Africa and had a really impressive record on funding action on HIV/Aids, we were asking big numbers $50 billion extra over the coming years and filling in details of how it would be spent. Instead of an agreeable but general set of discussions, we were putting real figures, real commitments and real deliverables on the table. George was nervous and I was absolutely aware that although others were going along, they were doing so in the belief that George would save them by volunteering to be the party-p.o.o.per. I also knew that if he agreed, no one else would dare disagree.

I was putting real pressure on, to be honest quite a bit above and beyond what the other leaders thought was desirable or necessary. Without George's backing, indeed, it would have been impossible. Even with it, there were limits, and I was significantly outside them.

The US style of summit negotiation is to be really difficult, be prepared to crash it, argue over every last word, then come in at the end and make everyone feel grateful they've even shown up. It doesn't win many friends but they know everyone hides in their slipstream. If they cave, no one will do their fighting for them, so they fight for themselves. It's fair enough, but it causes anxious moments for any summit host, including me. I knew if push really came to shove I could probably square George, but we were going for both climate change and Africa and he might just think one was enough, whereas I wanted both.

Also, once inside a process, people find it really hard to extricate themselves. George knew that from the moment he conceded, he was on a travelator that would take him a long way as indeed he went, two years later in Germany. He knew that if he agreed this process now with a statement that acknowledged the seriousness of the challenge and the fact that it was essentially man-made, he was locking in the US. And he never hid behind Congress. If he said he would do it, he would actually try to do it rather than just agree in the knowledge that others would block and save him from delivering.

The G8+5 was a crucial forum in which debate and discussion between the main emitters could happen reasonably informally. As I never tired of pointing out to people, it was a fat lot of good over a hundred nations coming together under the UN to agree a climate deal if the US wasn't part of it, and India and China weren't willing to accept any forward obligations to reduce emissions. This is why to this day, no matter how many countries have ratified Kyoto, very few Britain being an exception have met their targets.

On Africa, I knew that without real figures it was going to be another 'poor Africa, we care so much about you' load of old rubbish in a communique that wasn't going to fool anyone. Bob, Bono and the NGO alliance had mounted an effective campaign, essentially going to each main nation in turn and trying to frighten the pants off the leadership by demonstrating the breadth of public support for action on Africa. It was done cleverly, with them always giving enough praise to the leaders to encourage them. With Bob and Bono at the helm, there would be a sensible debate. If we delivered, they'd say we'd delivered. If not, they would condemn us. Fair enough. The Greens would be opportunist even if George came dressed in sackcloth and ashes, pleading forgiveness for his neocon past and said henceforth all Americans would give up the cars and drive wind-powered scooters.

Over time, I'm afraid I came to dislike part of the NGO culture, especially the Green groups. NGOs do a great job, don't misunderstand me; but the trouble with some of them is that while they are treated by the media as concerned citizens, which of course they are, they are also organisations, raising money, marketing themselves and competing with other NGOs in a similar field. Because their entire raison d'etre raison d'etre is to get policy changed, they can hardly say yes, we've done it, without putting themselves out of business. And they've learned to play the modern media game perfectly. As it's all about impact, they shout louder and louder to get heard. Balance is not in the vocabulary. It's all 'outrage', 'betrayal', 'crisis'. They also have their own tightly defined dogma and conventional wisdom which, if you challenge them, they defend fiercely not usually on their merits, but by abusing your motives for challenging them. On Africa, I tried constantly to get them to see free trade, with aid for trade, as an essential African interest, but it was virtually impossible. Part of their coalition basically took the position that 'globalisation is a rich-country conspiracy', and challenging that was to fracture their support. So they resisted. is to get policy changed, they can hardly say yes, we've done it, without putting themselves out of business. And they've learned to play the modern media game perfectly. As it's all about impact, they shout louder and louder to get heard. Balance is not in the vocabulary. It's all 'outrage', 'betrayal', 'crisis'. They also have their own tightly defined dogma and conventional wisdom which, if you challenge them, they defend fiercely not usually on their merits, but by abusing your motives for challenging them. On Africa, I tried constantly to get them to see free trade, with aid for trade, as an essential African interest, but it was virtually impossible. Part of their coalition basically took the position that 'globalisation is a rich-country conspiracy', and challenging that was to fracture their support. So they resisted.

It's like the Greens over nuclear power. The case for nuclear power is now so overwhelming that frankly it is almost irresponsible faced with an energy crunch and climate change to oppose its development. I bet many of them know that privately, but it would be such heresy to say so and would divide the movement.

The point I am making is that there's as much politics in NGOs as in politics sometimes more and they are treated as objective observers when they simply aren't. Partly they campaign for a cause, and partly for vested interests. However, this doesn't mean that everything they say is wrong, and they are part of a healthy democracy (this time I mean it).

At Gleneagles we were lucky to have some bright, warm weather, and would sit out in the sunshine or at least the others did. I would get up in constant agitation, flitting from the detail of the G8 to the perpetual speculation about the Olympic decision eagerly awaited by crowds in Trafalgar Square and the Champs-Elysees. The first intimation of the result came through: Moscow was out, then New York.

The tension was now very thick, and my staff gave up trying to talk to me about Africa and climate change since I was talking gibberish back to them. It was obvious from my many conversations with Latin American members of the IOC that if it came down to a contest between London and Madrid, they would back Madrid (Spanish speakers sticking together), whereas if it was London and Paris, they might well back us. It was plainly close. Like all electorates as small as this, there were naturally more votes pledged to the key contenders than there were voters. Every time Seb told me how many firm pledges he had, I would give a hollow laugh as would anyone who had ever been through a Labour Party selection process.

Around 10 a.m. the news came through that Madrid were out. It was us and Paris. It wouldn't be long now. Jo and the team went off to watch the announcement on television, but I couldn't bear to. I was outside when Jonathan Powell, who was irritatingly calm, joined me. I don't think he cared greatly. When the talk in the office turned to football, as it usually did at least once a day, Jonathan would put his fingers in his ears as if to say please talk about this elsewhere, some of us have work to do. His phone rang, and he took the call with much indifference; then somewhat conversationally, as though he had just been told that the 4 p.m. appointment had moved to 4.15, he said, 'Oh, we won, did we? Good, OK.'

I, of course, shot up like a rocketing pheasant on one of the nearby moors. Oddly enough, at that moment I remembered the time when, aged twelve, I found out I had won an exhibition to Fettes, running round our garden in Durham in sheer delight and of course relief, the draining anxiety replaced by joy. I think I danced a little around Jonathan and then hugged him. Jonathan is not a natural hugger; but he was there, and he got hugged. Then the others came running through, and of course were very willing to be hugged.

It was a great victory, a stellar victory indeed. To be honest, I knew also that although the G8 would naturally still be a big hurdle to leap, this was going to relieve the pressure on me. The phone calls of celebration were made, interviews given, the crowds in Trafalgar Square addressed. I could turn back to thinking about the G8 in an optimistic, confident frame of mind.

One of the first to arrive for the summit was Jacques Chirac. I felt genuinely sorry for him no, I really did. He had lost the referendum on the EU treaty, a terrible blow and I am sure a deeply felt, personal rebuff from his own people. Now this. And because I had been so high-profile in spearheading our bid and he had led his, it would be doubly humiliating. I would have felt gutted in his place, really low beyond low, actually.

But whatever else you may say about Jacques, he has courage and he is a pro. He turned up and was immensely gracious, congratulating me personally as well as the country, wishing me all the best and doing so with dignity and sincerity. I don't know whether in the privacy of his room he chewed the carpet and beat his fists on the floor, but I suspect not.

He had been a minister in the 1960s, and had been prime minister when I was a barman in Paris thirty years earlier. He has seen it all in fact, he's probably seen it too much, but one advantage is he's not fazed. In defeat, he was rather magnificent. He also always had one great attribute, I thought: he looked like a president, spoke like one and carried himself like one. His policies in my view were another thing, but as a personality he was the part. When he fought Lionel Jospin for the presidency in 2002, Jospin being the socialist prime minister in the nonsensical cohabitational arrangement that the French system can give rise to, the polls were close. But I was always sure Jacques would win, and when people would ask me why, I could only say: because he looks like a French president, whereas Lionel looks like a French professor; and the French want their presidents to be, well, presidential. Like Mitterrand.

The summit was to begin with a sumptuous dinner hosted by the Queen. Beforehand, George and I had a drink together with Cherie and Laura. I could see he was going to help and, of course, Cherie and Laura always got on really well. Our mutual friend Bill Gammell dropped by. Bill was becoming richer by the minute, having bought some oil concession off Bangladesh that no one else wanted and which turned out to be far better in deposits than anyone antic.i.p.ated. 'We made the wrong career choice, George,' I said after Bill left. He agreed, but neither of us meant it. Politics is voluntary.

As if Jacques didn't have enough problems, a few days earlier he had reportedly joked about British food in some unguarded remarks to Vladimir Putin and Gerhard Schroeder, effectively saying that you can't trust people whose cooking is so bad. For good measure he had also put the Finns in the same bracket. Personally I didn't give a d.a.m.n and thought it was quite funny, but of course everyone had to pretend to be thoroughly outraged and get very pompous. The fact that Jacques denied the remarks mattered not a bit, and various celebrity chefs, a.s.sorted cooks and general French-haters were wheeled out to condemn this monstrous attack; and the Finns, I think, really did take umbrage. The Finnish prime minister later told me solemnly that this had been a very big issue in Finland (I thought, Blimey, get a life).

As we sat down to dinner with the Queen, the j.a.panese prime minister Junichiro Koizumi hit on a great line of banter. Koizumi is one of the most interesting people I have ever met in politics, and certainly unlike any other j.a.panese politician I had met till then: a great leader, very lively, with an unusual personality. As he tucked into the first course, he said loudly in his halting English across the table to Jacques: 'Hey, Jacques, excellent British food, do you think?' followed by peals of laughter. Jacques looked at him a trifle acidly, forced to join in the joke, while protesting to the Queen that he had never actually said what it was alleged he had said. 'Said what?' she asked, being the only one not to have heard the story, thus necessitating the whole thing being explained again, much to everyone's amus.e.m.e.nt especially Koizumi's, who realised he was on to a rich vein and exploited it mercilessly, punctuating each course, and at times virtually each mouthful, with raucous comments about the brilliance of the cooking, until I thought Jacques was going to take out his aide-de-camp's gun and shoot him.

These G8 dinners are always weird affairs. The leaders are usually a little jet-lagged, they have to keep an eye on the agenda and at Gleneagles especially so. The surroundings are invariably grand, but the publicity is always about how grand, and inevitably the question is raised about the cost of staging the summits. Of course the big cost is security, yet somehow this is the leaders' fault for having the temerity to meet and talk about world affairs, rather than that of the motley variegated protesters who, unrestrained, could run amok. It's kind of a mixture of a very fancy busman's holiday, a workshop conference and a big political deal. And you are never sure how it will work out.

The opening dinners tend to be fairly convivial give leaders a drink or two and they are almost human but as the crunch comes in the following days, they can get more guarded. This dinner was good. The Queen handled them all well, though some guests didn't always quite know how to handle her. Some got matey with her. Now let me tell you something: you don't get matey with the Queen. Occasionally she can be matey with you, but don't try to reciprocate or you get The Look. I watched with some amus.e.m.e.nt those who understood the difference between a queen and a president and those who didn't. Both are heads of state, but the Queen is the Queen. That's royalty, not some jumped-up elected pleb. And don't you forget it.

After dinner I went back to the suite to work on the agenda. There was still a lot to do people were apart on numbers on Africa and there was still stiff resistance on climate change. I slept not long but well, was up early preparing, still elated, but now really starting to focus.

The first meeting was a bilateral with George. Pretty quickly we threw out everyone else and had breakfast together. I needed to get the feel for whether he would cross the line and agree to be part of a dialogue with the express objective of reaching a new post-Kyoto deal. He wouldn't commit to a target now, that was understood, but would he be part of a process where eventually that would be on the agenda? He was more or less there on Africa.

In handling the whole G8 agenda, I was supremely blessed by having a fresh and really capable team around me, including Sir Michael Jay, who had been amba.s.sador in Paris and was now head of the Diplomatic Service. To my surprise and delight, he agreed to take on the role of G8 sherpa (i.e. the government point person for the preparation of the summit). This was way below his pay grade, as it were, but it demonstrated our commitment and the importance we attached to the summit. He had the right blend of experience, weight and conviction.

He was supported by Justin Forsyth, who had joined from Oxfam. In other words, he was from the bete noire NGO movement. He turned out to be fantastic; he knew them all, was one of them, could spot their tactics, identified accurately their foibles and fault lines and was a really sharp non-political politician. He did the politics of the NGOs, Michael did those of the governments. And Sir Nigel Sheinwald, my foreign policy adviser at Number 10, kept his beady eye on it all and followed through notably with the Americans in the way only he could.

George and I did a short press conference together. He had to explain why he had knocked over a policeman while he was on a bike ride in the grounds the evening before. It could only happen to George. Typically, he spoke to the policeman in hospital and was very self-deprecating about it, but naturally the whole thing had been treated in the media as if George had come to Gleneagles with the express intention of finding a Scottish bobby to knock over and probably that afternoon would be lining up a few more and mowing them down.

Nothing seemed set to disturb the mood of buoyancy. A bit of pushing and the G8 would come together, which would be a landmark in summitry. I knew the risks on making it about what the big and powerful nations could do for the world and abandoning its traditional economic role. I knew it was the right gamble to take. I felt confidence surging back through me, in my own judgement, in my self-belief and in my destiny.

I walked the few steps to the little press briefing room, where I was to meet President Hu of China. He tended to be very formal, but very much on top of his brief and, I think, quintessentially decent. We began our session with my asking him to appoint someone we could liaise with more informally so that UK/China relations, radically improved since the return of Hong Kong, could move to a new level. He made a suggestion, we agreed and started to move on to the G8 agenda.

China was very reluctant to move on climate change because it was wary of being bound into obligations inappropriate to its stage of economic development. The Chinese were terrified of being pushed to accept something that was inimical to their number-one priority: growth. They had over 60 per cent of the population still earning a living from agriculture (the US and the EU had around 3 per cent) and wanted to move vast millions of people from the land to cities. Without strong economic and industrial growth and hence greater energy consumption it was an impossible task. The Chinese doubled their coal consumption between 2000 and 2006. They knew that consenting to be part of a dialogue with the aim of an agreement at the end was a lot less innocuous than it appeared, so they were understandably cautious, yet were also feeling their power; sensing the responsibilities that went with it; recognising that they couldn't be outside and inside the power club at the same time. I thought I could get them to come on board, provided I didn't overegg it or ascribe to them positions they weren't ready for.

Fifteen minutes in, Jonathan pa.s.sed me a note. It simply said that there had been an incident on the Tube. Possible casualties. Might be an accident, might not. Instinct said it wasn't.

Suddenly Jonathan left the room and then came back in looking agitated. I apologised to President Hu, explained the note and asked Jonathan if we knew anything further.

'There is more than one explosion,' he said.

Oh G.o.d, don't let it be a terrorist attack, not that, not here. What I always feared, so obvious for them, so divisive for us. Right now, at this moment, there are people I don't know whose lives have just changed forever, perhaps ended forever, the world forgotten in the extinction of one human being's hopes, dreams and ambitions, all ended for reasons they will never know, nor understand, nor can ever argue about. Terrorism is the ultimate injustice: the targeting of the innocent precisely because they are innocent.

I got up and asked the president's indulgence but I had to go and check it all out. On the way up to my room, clutching the mobile Jonathan gave me and getting the barest details, I b.u.mped into George. He had heard already, of course. 'Terrorist attack?' he queried.

'Could be an accident,' I said. But we looked at each other and knew that it wasn't.

By now it was clear there had been three attacks, all on the London Underground, all at peak rush hour. I spoke to Charles Clarke, who was as I expected: focused, not panicking, and trying to think through the logistics of the response. Shut the networks, train stations of course, but what other precautions? What help would the emergency services want?

'How many casualties?' I asked.

'I can't tell,' he said.

'Deaths?'

'Bound to be, I'm afraid.'

'How many?'

'Don't know.'

Pointless questions and pointless answers; no one knew.

At first, we thought it might be a handful of people, each one a tragedy but less than the worst case. The worst case would be very bad at that time of day, between Aldgate and Liverpool Street, Russell Square and King's Cross, Edgware Road and Paddington all very busy commuter journeys.

Around 10 a.m., news came through of a fourth explosion. This time it was on a bus at Tavistock Square just south of Upper Woburn Place, somewhere I used to go regularly as a barrister, where the old industrial tribunal used to be. I thought inconsequentially of all the times I had been there, and pictured it now in my mind, the bus with the roof blown off, limbs, bones and blood strewn everywhere. And for what? In the name of G.o.d?

Anger, pity and determination jostled like queue-jumpers barging into each other. I took a deep breath. Cut out the emotion, just think. Get a sense of the magnitude, work out the emotions of the country but do so in a way that leaves you free to describe them, but not to share them except for the purpose of description, so as to leave your mind clear. Do I leave the G8? Do we cancel it? How can I chair it waiting for news? Do we hand the enemy a victory by altering our arrangements? Do we show insensitivity to the victims by carrying on?

I know it sounds callous but calculations have to be made. There will be a time for me to weep later. Now you are the leader, so lead.

Slowly, by the odd Socratic process that takes place in a crisis, we put a plan together. The magnitude was plain: not the worst case, but fifty-two dead and many more injured, and heaven only knows how many more traumatised. Fifty-two dead people. Fifty-two people with families, friends, girlfriends, boyfriends, children. Fifty-two people who used to engage in all of life's fullness and variety. Fifty-two people who had got up that morning not knowing it was the last time they would ever wake up or kiss someone goodbye.

I called the other leaders together and explained the situation. I was in a genuine quandary as to whether to leave the summit. In hindsight it was obvious; I should return to London. It didn't seem like it then. It was Jacques who was most emphatic: you have to go back, the British people will expect it. What about the summit? I asked. We agreed it would be chaired by Sir Michael Jay.

I did some very brief media, after telling them I would do a statement later in Downing Street once I knew the facts. Charles would take care of the House. I boarded an RAF helicopter, and from Dundee airport we flew to Northolt and thence to Downing Street.

Even at moments of the highest tragedy, there can be moments of absurdity. The French amba.s.sador Gerard Errera asked if he could come back with us on the plane. We naturally a.s.sented. As we flew down, the steward asked us if we wanted anything to eat as we had all missed lunch and were hungry. Having no time to prepare anything, lunch consisted of a bowl of stale crisps, some forlorn old salted peanuts and a few sandwiches which would have been rejected by British Rail in its heyday. Errera momentarily caught my eye and his face twitched. Had we brought a libel case against Jacques for his attack on British cuisine, Errera would have been the first witness for the defence.

Back in Downing Street we a.s.sembled the facts as best we could, and convened the emergency Cabinet Office Briefing Room (COBR) meeting. The worst thing was not knowing what else was out there. Was that it? Who and why? It was obviously part of the al-Qaeda network, but who was it specifically, here or abroad? It was some time before all these answers could be given. In the aftermath, we had several weeks in which there were calls threatening new attacks, or intelligence of such an intent. It was a nightmare. Each call could be a reason for shutting down the airport or transport infrastructure, or closing down city centres. We had the tragic killing of the Brazilian student Jean Charles de Menezes on 22 July, which turned out to be a terrible error but where I also felt desperately sorry for the officers involved who were acting in good faith trying to keep the country safe. On one occasion we had a COBR meeting about the latest threat that had been made, although the intelligence seemed flimsy. Ignoring it was hard. Acting on it was also hard. Yet again we would have to shut down the Underground. So: act or ignore? I looked round the table and finally asked Ian Blair, the Metropolitan Police commissioner who had done an excellent job through the attacks and after, what to do. 'I'm afraid this is your call,' he said. I decided not to act, but I pa.s.sed a very restless and anxious night when the time of the threatened attack came.

All the way down in the plane from Scotland, I had thought carefully about how we should respond as a nation. Jonathan, Charles and others could take care of the detailed, immediate response; what I had to focus on was how to express our thoughts as a country. This wasn't about 'emoting' or 'empathising', as people often stupidly and cynically say. At times like these, it is about defining the feeling so the reaction can be shaped and the consequences managed. Because there would be consequences from fifty-two totally innocent people dying, the worst ever terrorist attack in the UK, worse than any Irish Republican attack in forty years of the Troubles.

People could react in any number of ways: there would be the anti-Muslim brigade; and there would be a response that said it's really all the fault of Blair and Bush (I could see this coming the moment parts of the media thought it safe); but most of all there would be the sense of despair and tragedy. How could this be done, and in London, the embodiment of a multicultural city, the place just lauded by the award of the Olympic Games, no less; and precisely because of its open, friendly and unprejudiced character? Unbelievable. First triumph, then tragedy.

I formed the view that the first good instinct of the British people Muslims, Christians, all of us would be to unite and close ranks against the extremists, to reject prejudice in favour of solidarity. I knew that after a while there would be a second emotion: anger and a demand for action to prevent the possibility of this happening again, by tough measures, including legislation. By this point of my premiership, the iron had entered my soul on the issue of liberty versus anti-terror laws. When Lord Hoffmann had described the anti-terror laws as more of a threat to the country than the terrorists, I just couldn't believe it, couldn't credit how a sensible person could say anything quite so grossly stupid. So I knew there would be a battle to come.

But I knew the first thing was to unify, so I gave the Downing Street statement which tried to do that and I think by and large did do it. Specifically, I paid tribute to the Muslim population of Britain. I had real doubts about some of the leaders of the community and how they were confronting or rather not confronting this extremism, but it wasn't the time to entertain such doubts. It was the time to let the Olympic spirit flow, through the tragedy as well as the triumph.

Late that night, I went back to Gleneagles. We had done what was necessary to show proper sensitivity to the victims of the appalling act of terror. Now we had to show that the G8 was our way of doing politics, and that also mattered. The contrast between our way and the terrorists' way was essential. We had to fight terror not just through police, intelligence and security services, but as I constantly reiterated, it was a battle of ideas. I didn't know if they had timed the attack for the G8, but that's when it happened; so we had to paint the contrast in the boldest letters imaginable. Good politics and evil. Stark. Simple. Undeniable to all but the deranged.

By the time I got back, it was clear that the consequence of the terrorism on the leaders was to bring out the best in them. They had reacted brilliantly, and with total solidarity. There was an implicit collective decision to support the G8 agenda and get a result. The African numbers came together. The G8+5 dialogue was agreed. Michael Jay was performing with great skill, but they were getting there through political instinct and a genuine revulsion at the horror. We weren't going to get everything we wanted, but as Michael said, it's eight or nine out of ten. And believe me, for a summit, any summit but particularly G8, that is a real result. In the end, it set a new standard for such summits and rightly was regarded as historic.

We a.s.sembled the next day for the final session and communique. I had the idea of doing a statement setting out our achievements and contrasting that with terror, doing it all together, leaders of the world united, and symbolically signing the communique to give it added resonance and credibility. That's what we did, forty-eight hours after I had heard the Olympic result, two days of the most extraordinary turbulence I had lived through in my time in politics.

On Africa, we agreed a comprehensive plan of action, based on the Africa Commission. We got the $50 billion uplift in aid, debt cancellation, commitments on Aids treatment, on malaria, on governance and corruption.

On climate change, we agreed to begin the G8+5 dialogue with the express aim of reaching a new global deal that would first slow down emissions and then cut them.

For good measure, we also agreed a package of support for the Palestinian Authority.

But most of all we stood up for proper politics. Even with all the suits, the paraphernalia of summitry, the flat words of the communique, the grand surroundings all looking like politics as usual, there was something felt by us all hardbitten and inured to most political emotions though we were that was true and real about what we were doing.

I did the press conference in the garden of the hotel. There was the usual nonsense from some NGO bloke about how we had all let Africa down, and the unusual riposte from Bob who basically tore the bloke's head off for being so negative and followed him down the path from the press area, shouting abuse as only an irate Irishman can.

I recorded an interview with Jim Naughtie for the Today Today programme. I like Jim, but I knew already where it was heading: if we hadn't gone to Iraq, we might have been spared this. It's a nightmare of an argument to deal with because, of course, at one level, if you don't fight these people, it's possible you don't feature so much on their hate list. But what does that say about how your foreign policy is determined? And you know that if you give even a sliver of credence to the argument, then suddenly it's our fault, not theirs, which is, naturally, the very thing they want. programme. I like Jim, but I knew already where it was heading: if we hadn't gone to Iraq, we might have been spared this. It's a nightmare of an argument to deal with because, of course, at one level, if you don't fight these people, it's possible you don't feature so much on their hate list. But what does that say about how your foreign policy is determined? And you know that if you give even a sliver of credence to the argument, then suddenly it's our fault, not theirs, which is, naturally, the very thing they want.