(This is a slightly longer version of a piece which appears in today's Sunday Times.)

Last Tuesday, around 200 assorted neoconservatives gathered in the Jubilee Room of the House of Commons to toast their ascendancy over wine and canapés, and to plot the next stage of American global dominion.

Paying no heed to the traditional niceties of politics, they came from across the party divide, but with one thing in common: a secret aspiration to impose America rule on hitherto free peoples.

I was there. I am one of those very neoconservatives. And today I expose the truth behind the plot to change the world.

The gathering was the London launch of the Henry Jackson Society, an organisation – at this stage little more than a website and a group of supporters – named after the great Democrat senator and anti-communist campaigner, Henry ‘Scoop’ Jackson.

Jackson was a traditional New Deal liberal, a trade unionist who believed in nationalisation and price controls, and a civil rights campaigner. But his real impact, and his legacy, lay not in domestic but international politics. He was an implacable opponent of the received foreign policy wisdom of détente with the Soviet Union. As the Henry Jackson Society’s founding statement puts it: “He believed that this was an unprincipled accommodation, which abandoned the wider cause of human rights, as well as compromising security. Jackson’s core belief was that democratic governments should consider the internal character of foreign states when dealing with them.”

Jackson’s message – the relevance of which is as great today as then – was that the supposedly ‘realistic’ approach of the likes of Henry Kissinger, which accepted that the Soviet Union was here to stay and sought to reach an accommodation with it which would lessen its threat to the West, was misguided both strategically and morally.

The parallels with today are striking. Perhaps the most interesting aspect of Tuesday’s gathering was that it was genuinely all-party. The event was hosted by two MPs, Michael Gove, a Conservative, and Gisela Stuart, a former minister under Blair. Denis MacShane, Europe Minister until June, is a signatory of society’s statement of principles.

The truth which I expose today is that the Henry Jackson Society is not a secret cabal designed, as one Guardian columnist put it last week, to create “a new governing consensus of the right” but quite the opposite. It has neoconservative members. But it also has social democrats and traditional conservatives. Socialists would feel comfortable with its aims - “the spread of democracy, using all realistic and available means - not only on idealistic grounds, but also because this is the surest guarantee of…security.” And it is not about American dominion but the very absence of empire. There is indeed a mission to change the world. But it is to rid it of tyranny and to give all people the liberty as we enjoy in the West.

The founding of the society, and the reaction to it, illustrates a fascinating – and potentially dynamic – development. As its broadly based membership shows, it is no longer possible to tell from someone’s political affiliation what their outlook will be on the basic issues of foreign policy.

It might, after all, be thought reasonable to identify democracy, freedom and human rights as key components of a left-wing approach. And yet the reaction to the Iraq war shows that no longer applies. At its most basic, had the Conservatives under Iain Duncan Smith not voted for the war in the House of Commons, Britain would not have been involved; Blair did not have sufficient votes on his own side. Some Labour MPs went along with the war because their Prime Minister asked for the support. But today, very few remain in favour of a war which freed Iraqis from one of the most murderous dictators in history.

Yet on the Conservative benches support from the likes of George Osborne remains steadfast – not just because of the geopolitical importance of Iraq and the war on terror, but specifically because of the merits of liberal intervention. Fighting, in other words, to secure other people’s freedoms – freedoms which opponents of the war such as Respect and many Labour members would rather did not exist.

Party affiliation is no longer an accurate indication of approach. My own realisation of that came in the wake of 9/11. I have always considered myself to be on the Left. After 9/11, I realised that the reaction of many, if not most, of my fellows was a variation on the theme of ‘America had it coming’. That was compounded over Iraq, where the liberal left ended up in bed not only with the traditional ‘realist right’ in opposing a foreign intervention, but also with militant Islam. Instead of fighting to bring freedom, they allied with an ideology which instructs husbands to beat their wives.

The earliest indications of this change came over Bosnia. The Douglas Hurd/Malcolm Rifkind approach, with a long Tory history, was to sit on their hands and oppose being dragged into a nasty foreign mess. What had human rights to do with British foreign policy? That stream of Conservatism has not gone away; both men opposed the Iraq War.

What has changed is that Labour’s own opponents of intervention in favour of human freedom now have the upper hand. After Blair, it is difficult to see from where else the moral lead for intervention will come.

Others, of course, take a very different view. Christopher Montgomery, a historian of the ‘realist’ school, whose book about Conservative leadership elections, The Crisis of Tory Leadership, is published next week, considers that the real divide is between those who “slavishly follow America” and those who stand up for Britain’s national interest. “There is no new divide or emphasis on human rights. In Bosnia, we were simply dragged in because of the dictates of an alliance with America.”

What is undeniable, however, is the intellectual ferment now occurring around these issues, of which the Henry Jackson Society is merely one example. Another is a timely and excellent new book by Oliver Kamm, Anti-Totalitarianism: the left-wing case for a neoconservative foreign policy, which argues that there has been a long left-wing tradition of “militant anti-totalitarianism”, but that there has also been a recurring temptation for progressives, critical of their own societies’ failings, to make excuses for the ideological opponents of Western liberal democracies. Kamm links this with Conservative realism (which he calls “amoral quietism”) and shows how the two very different ideological roots end up in the same place.

The parallels with Israel are far from exact, but Ariel Sharon’s resignation last week from Likud to form his own party, with an explicit purpose of drawing members and support from both Likud and Labour, certainly shows how labels can obscure more than they reveal. Sharon’s recent coalition with a Shimon Peres-led Labour Party was itself the result of the two men coming together over an issue – relations with the Palestinians - which crossed party boundaries.

There is a similar, albeit less obvious, effect in domestic policy. Take immigration. The government’s loosening of the limits on immigrant workers is supported by many Conservatives who, believing in the benefits of free markets, favour a still more open immigration policy than we have today.

But the Conservative position in its election posters was a traditional right wing message that "It's not racist to want to control immigration”. It is not, however, just Conservatives who are expressing their objections to immigration. Last month Polly Toynbee, the high priestess of the Guardian, wrote that “It is shocking that 30,000 of the 70,000 workers being employed to start work on transport infrastructure for the Olympics are to be east Europeans, not impoverished Londoners” – a theme which could have come straight out of the BNP’s mouth. Her concern, of course, is very different from the BNP’s, if equally economically illiterate: “It is impossible to know what level wages might be at or how many unemployed might have been tugged into jobs at higher pay rates had Britain kept its doors shut to new EU citizens until their countries had caught up economically.” A more subtle anxiety has been expressed by David Goodhart, the editor of Prospect, who has written about the cultural impact of mass immigration.

So the far right’s hatred of foreigners has been joined by the more nuanced worries of liberals. But whatever their intellectual roots, both amount to the same thing: there are too many of them here.

Foreign policy, the more interesting area, has not been an election decider in Britain for many years, and the once trendy prediction that the splits over Europe would lead to a political realignment has not been borne out. Jackson remained a registered Democrat throughout his life. But although his approach had once been relatively mainstream within the Democratic Party, the aftermath of the Vietnam War, the rise of George McGovern and the peaceniks and the moral relativism which gripped the Left in the 1960s and 1970s all symbolised how traditional party positions and alignments were shattering.
On the one hand stood the peaceniks – the McGovernites and their European equivalents in the Campaign for Nuclear Disarmament - who did not merely tolerate the Soviet Union but opposed any real attempt to threaten it as illegitimate interference in the sovereign rights of another (and, in some minds, finer) nation.

Just as Conservative realists and Labour opponents of intervention end up in the same place today, so the Nixon and Kissinger policy of détente had the same effect as the McGovernites – not toppling the Soviet Union but entrenching it. Détente was the high water mark of so-called realism, which buttressed a regime which enslaved and murdered millions and which sought to impose its tyranny across the planet.

But there were others - led by Jackson - who were repelled by this alliance of cynicism, which both ignored the victims of the Soviet Union and bought short-term peace at the cost of long-term defeat.

The emergence of Ronald Reagan, who was as hostile to his Republican predecessor Nixon as he was to his immediate and ineffectual Democrat predecessor Jimmy Carter – who claimed to put human rights at the centre of policy but who lacked the fibre to follow through – transformed politics.

Many of Jackson’s supporters (such as Richard Perle, who became a key player under Reagan) saw that it was the Reagan Republican party which stood for what was once the natural preserve of progressives and the Democratic Party: real progress in human rights and liberty. Jeanne Kirkpatrick, Reagan’s first US Ambassador to the United Nations, remained a registered Democrat throughout her time in Reagan’s Cabinet.

Could we see such realignments here? “Yes”, thinks Kamm, “as part of a more general realignment between the forces of openness and those of reaction. Among the first group are advocates of, for example, greater economic integration and trade, and among the second are those who stress a narrow conception of national interest in the name of realism. At the extreme in the second camp, you find the alliance of far-Left and theocratic reactionaries.”

Far from it being the Left which placed the ending of tyranny at the centre of foreign policy, it was Reagan who memorably, and accurately, described the Soviet Union as an evil empire. And it was Reagan who stood at the Brandenburg Gate in 1987 and urged Mikhail Gorbachev to “tear down this wall”.

The Soviet Union did not collapse because of the liberal left consensus – which the media would implicitly contrast against the insane cold war warriors. Reagan and Baroness Thatcher, his soul mate, were portrayed as dangerous, militaristic right wingers as the mainstream left protested in Europe against the incendiary deployment of Cruise missiles.

Had the mainstream had its way, the Soviet Union would remain in place today, propped up by détente. And there would be nothing former about the now former members of the Warsaw Pact.

That there are contemporary supra-party alliances over foreign policy is clear. What we do not yet know is whether - as over Europe - existing party politics will nonetheless remain in tact, or whether there will indeed be a realignment between the forces of openness and those of reaction.