I have just listened to the extended edition of the BBC's World at One with a full hour of responses and reflections on Margaret Thatcher after her death was announced this morning. Three crucial words were missing. In all likelihood they will go unsaid in the many reflections, obloquy and eulogy, that will pour forth from left and right. Yet without them the policies that made her were inconceivable.

North Sea Oil.

Her 'conviction' would have been nothing but folly without the North Sea's black gold. It was oil revenues that bankrolled the unemployment, the destruction of manufacturing, the high-exchange rate, the termination of British coal mining, and the big-bang that turned London into a capital of global neo-liberalism and pumped growth into the South-East in the early 1980s.

As North Sea Oil came on stream bringing in an estimated £70 billion in revenues, it turned the UK into an OPEC country, an oil-exporter, and it overturned a chronic balance of payments problem rooted in the post-war period of clinging to imperial over-stretch.

What may seem odd to many who do not recall the seventies and their follies, brilliantly captured by Francis Wheen's Strange Days Indeed and How Mumbo-Jumbo Conquered the World, is the belief in Thatcher as a saviour. The post-war settlement created after 1945 was indeed in a terminal crisis. Its cause was not Trade Union power, which was a symptom of the disintegration, the vast residue of Britain's early proletariate left by the receding tide unwittingly memorialised by Henry Moore. But crisis there was and she became the solution after her victory in the Falklands War.

On the left and outside official Labour, there were four broad responses to Thatcher, personified by Tony Benn, Stuart Hall, Eric Hobsbawm and Ken Livingstone's. Benn was for traditional left populism with a democratic language entirely new to 20th century British politics, but this was captured by the far-left and in particular by the miners' leader Arthur Scargill, an anti-democratic syndicalist who orchestrated its destruction.

Stuart Hall and Eric Hobsbawm together gave Marxism Today its influence over a Labour Party trying to modernise. Hall first coined 'Thatcherism' as a term and saw it as an ideological force. He recognised it as gaining its influence thanks to the "decomposition of the labour movement" which permitted what he termed, with insight, Thatcher's "regressive modernisation" - her capacity to forge a new form of capitalism under the guise of traditional institutional mores.

Hobsbawm's view was that the "march of labour" had been "halted" and now faced a counter-attack thanks to what it had achieved. He saw Thatcherism as a threat akin in a way to Fascism, demanding a defensive 'popular-front' type response and thus a progressive alliance of Labour and Liberal-Democrats to secure what had been gained. The difference was important. Hall saw the rise of Thatcherism as thanks to the chronic weaknesses of Labour and the left while Hobsbawm saw it as a response to its strength and achievements.

Livingstone, though more opportunist as befits a politician then leading London as the head of the GLC or Greater London Council, gathered new social forces behind him that were scorned by the traditional left and social democrats. Unwilling to tolerate any opposition to her rule, Thatcher abolished London's Council and sold off its County Hall to a hotel and aquarium.

My own view was that there could be no successful response to the rise of Thatcher and Thatcherism without challenging the undemocratic nature of the British state which she deployed with such effect (allowing her, indeed, to abolish municipal government across a great city, unthinkable elswhere). "It's the constitution, stupid" had to be the starting point for any social and economic response. This eventually fed into Labour thanks to John Smith, before Blair decided to become Labour's Thatcher with a social face.

In looking back on what she stands for one thing needs to be recognised by those of us who opposed her (and I got in my own face-to-face at the very last moment of her power in Paris).

This is not that she had 'conviction' while all those around, before and since, fail to stand for any principles at all. She was not alone in having courage and if anything had far more cunning, deviousness and patience than most. An analysis of her mastery of the timing of the post-Falklands 1983 election, published in the new edition of Iron Britannia, demonstrates her obsession and supremacy in these arts. Rather, the love of her leadership introduced an unhealthy Führerprinzip into British politics which was and remains a sign of the very British disease that struck official politics in the 1960s. Indeed from the Pergau Dam to the sale of military equipment to Saddam Hussein investigated in the Scott Report, Thatcher was involved in corruption and illegality from which she only just escaped official censure.

No, what undoubtedly her character helped to unlock in these benighted isles was energy. She broke the suffocating integument of elite consensus and the closed, hierarchical world that, ironically, went back to the Second World War she lauded. In doing so she released energy across the country, for good as well as ill. The energy of entrepreneurs, of city slickers, of New Labour, of rioters, in music and on the stage, of speculators and welfare cheats, of working men and women who bought their own homes.

But the source of this energy was not her inner character but money, lots of it. And she even personified this in her own migration from being Margaret Roberts to Margaret Thatcher. She was not just the grocer's daughter who got her way by sheer graft, she was also an oil millionaire's wife.

At a crucial point, in October 1981, prior to the Falklands as her predecessor Edward Heath openly attacked her, she asked, "What great cause would have been fought and won under the banner 'I stand for consensus'?" The answer was, of course, the Second World War itself, that saved the British state. In reflecting on this in Iron Britannia I tried to decipher the legacy of what I termed Churchillism on which she drew but subverted. This was the paradox of Thatcher: that she destroyed what she appeared to preserve. Britain may have been saved by her but it will never recover from the experience.

PS: Al Jazeera asked me to go on as I was writing this and here are further reflections since. Thatcher did a lot of undeniably immoral things such as supporting Pol Pot, as documented by John Pilger; and undemocratic ones such as pushing through the Poll Tax knowing it would drive poorer, Labour voters from the electoral register, as I have documented (see footnote 10 here). But those like Owen Jones who simply assault her from the left have to ask why she was also, despite what she did, popular with a segment of hard-working working class and natural labour supporters. There was a definite sense of integrity, of a tough person fighting to get her way, Peter Oborne's pangyric captures this: the need for honest graft as distinct from profiteering, that she personified. Accusing her of 'hypocrisy' in this respect simply boomerangs, as to argue that she was not really like this endorses the values of what she claimed. It was this challenge that provoked the energy and I should have included novels to the list, see Ian McEwan's thoughtful reflection. On the question of oil revenues, George Eaton helpfully demonstrates how much she had to play with and spent in public revenues especially on unemployment, while to my surprise it turns out that Tony Blair spotted and analysed the decisive role and sweeping impacts of North Sea Oil in the days when he wrote for the London Review of Books - it is his estimate of £70billion I quote above, worth double as it reversed a chronic balance of payments imbalance.

What all this brings home are the larger forces that Thatcher personified. The first of these was globalisation, a notoriously unconservative, radical force. The second, and linked to it, was a hostility to the State rooted in the cultural shifts of the 1960s, which she also reflected (something I have long argued, she gave her first speech criticising the power of the state to the Tory Party Conference in... 1968).

See Anthony Barnett on Al Jazeera on Thatcher and what the world should know about her legacy.