The defeat of British Prime Minister David Cameron in Parliament over his plan for "humanitarian intervention" in Syria to "protect civilians from President Assad's chemical attacks" is one of the most significant parliamentary votes in recent years.
It means that Cameron, one of the most aggressive advocates for military intervention, has been prevented from participating in any United States-led operation in Syria. The divergence between London and Washington on this matter has echoes of the 1960s, when Prime Minister Harold Wilson successfully rebuffed President Lyndon Johnson's pressure to send British troops to Vietnam. Some writers have gone all the way back to 1782 and the American war of independence in search of a parallel.
A defeat of this magnitude has many consequences for foreign and domestic policies, as well as for Cameron's own authority. The atmosphere before the debate was poisoned by extraordinary behaviour outside Parliament. As the prospect of defeat became distinct in the hours before the vote, expletives were used against the opposition Labour Party leader, Edward Miliband, in private news briefings. They originated from the prime minister's official residence and the Foreign Office.
In an ill-tempered phone call, Cameron accused Miliband of siding with Russia and giving succour to Vladimir Putin. Such low punches were bound to unite the opposition, and alienate the undecided, and even friends, as seen in the parliamentary vote and after.
Immaturity and misjudgement
The use of raw language by unnamed people close to the prime minister reflects the degree of the government's immaturity and misjudgement of the mood in Parliament and outside. The doubters included many in his own party and his coalition partners, the Liberal Democrats: Thirty Conservative and nine Liberal Democrat MPs voted against the government. Some ministers missed the vote. It showed how divided Cameron's troops were, how high the stakes became, how desperate the battle to win, somehow, anyhow - and why the atmosphere turned so unpleasant.
It was largely Prime Minister Cameron's own making, for he and his hawkish Foreign Secretary William Hague were the two leading architects of the policy on Syria. Together, they had pushed an unsure President Obama to an interventionist position. Cameron and Hague had persuaded the White House to intervene in Libya in 2011. They almost succeeded in doing so again on Syria, before the British Parliament stopped them. By then, however, they had walked Obama far enough not to be able to reverse the US position without appearing politically impotent.
Cameron recalled Parliament to debate Britain's participation in the false hope, as it turned out, of getting the MPs' backing for intervention in Syria. Assertions of Britain playing its essential role as befits a "major power on the world stage" were heard again and again.
Cameron and Hague hopped from one justification to another during the debate in the House and outside: The ban on chemical weapons has to be upheld; Britain cannot sit idly by while innocent civilians are slaughtered; Britain has a responsibility to protect; the United Nations Security Council does not matter; we do not plan regime change, but Assad must be punished.
When the crunch came, Cameron and Hague failed to deliver. Their arguments were vague and predictable. Their legal justification was far from compelling and unconvincing to many. Their assertions that Britain was already certain of the culpability of Bashar al-Assad, although the UN inspectors had yet to decide whether chemical weapons had been used, sounded bizarre.
Why was the "use of chemical weapons" in Syria's civil war - the "red line" - unacceptable while mass killing by all sides, abduction, torture and forced expulsion of civilians were not? Absurdities of this kind in making the case for intervention are there for all to see. There will be no UN Security Council approval or NATO umbrella - instead, there may be only a "coalition of the willing" like the US-led invasion against Saddam Hussein in 2003.
Cameron exhibited too much hubris and undisguised eagerness to look like a war leader in the mould of Winston Churchill, Margaret Thatcher or Tony Blair - who is a much diminished figure in Britain today after his role in the "War on Terror". The evidence presented by Cameron to Parliament failed to convince members, who knew public opinion was strongly opposed to Britain's involvement in another war. Blair's advocacy for intervention in Syria reminded many people of Iraq.
Britain's appetite for punching above its weight has come to an end. One commentator on the left said that Britain's illusion of empire was over. The Economist, the pillar of the right-wing British establishment, described Cameron's defeat on its website as "The vote of shame", and the Conservative-Liberal coalition is now deeply traumatised as accusations and counter-accusations abound.
In-depth coverage of escalating violence across Syria
For all this, the oposition Labor leader Miliband deserves credit. He is not like left-wing Labour politicians of the past, offering an alternative to neoliberal militarism. It is a welcome change that is good for democracy.
Meanwhile, the Conservatives must try to rebuild their party and the Liberal Democrats, the junior partner in the Conservative-led government, face an existential threat. Having sacrificed their principles while in power, the Liberal Democrats will face a tough election next time around.
In an open display of bitterness, former Liberal Democrat leader Lord Paddy Ashdown - now a party grandee - said he was ashamed after the vote on Syria. The Guardian was right to rebuke him for lecturing the nation. On the contrary, the newspaper declared: "We should feel ashamed that our instinct for legitimacy and our patriotism have been too often and too cheaply taken for granted ... Britain's mood is not never again. The mood is not now, not again, not like this."
Deepak Tripathi, fellow of the Royal Historical Society and the Royal Asiatic Society of Great Britain and Ireland, is a British historian of the Middle East, the Cold War and America in the world.
Follow him on Twitter: @Deepak_Tripathi
The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.