Is the UK "hugely diminished", as former Liberal Democrat leader Paddy Ashdown has argued, after the House of Commons rejected the principle that military action could be taken to protect Syrian civilians?

The argument is that failing to act will damage Britain's standing in the eyes of the world. This is a risk. If international conventions such as the ban on chemical weapons are breached and no action is taken, there seems little purpose to having them.

But precipitate action without proof carries an equal if not greater risk. By intervening in Iraq on evidence that turned out to be largely false, the UK Government also damaged our standing in the eyes of the world, arguably with more lasting consequences than might have been expected from any failure to act.

If hard evidence linking the Assad regime with the chemical weapons attacks were available, the outcome of the vote on Thursday would almost certainly have been different.

Had there been a UN resolution endorsing military action in Syria (however unlikely that scenario) that may also have changed opinions and swung a tight vote. But that evidence is not available. Nor is there international agreement in favour of intervention.

The UN inspection team will not provide that evidence either. It will establish only whether chemical weapons were used, an outcome in little doubt.

The conclusion from Britain's Joint Intelligence Committee is that it is "highly likely" the Assad regime was involved in the attack last week. But that is based on first-hand evidence, partly on speculation no other group had the capacity to launch the attack.

This finding was wrongly hailed by David Cameron as "compelling and conclusive". Not only is this misleading; it also has awkward echoes of the evidence for weapons of mass destruction in Iraq in 2002. The legacy of the Blair Government's dodgy dossier and other justifications for intervention in Iraq and Afghanistan hang heavy over the debate on Syria, as does the sense a war-weary public is tired of seeing the bodies of servicemen and women being repatriated from conflicts overseas it feels are distant and where UK strategy is unclear.

David Cameron's authority has been undermined by Thursday's vote, despite attempts to recast his role as one of allowing Parliament to decide. Meanwhile, Tory whips will be alarmed, as it is a truism that backbench rebellion can become a habit.

It is Labour leader Ed Miliband, by appearing to inflict defeat on the Prime Minister and insist that Parliament listens to public opinion, who emerges strengthened.

On the global front, it appears that the United States will take military action with or without Britain's support.

The special relationship between Britain and the US will be strained. It was notable that Secretary of State John Kerry last night referred to France as his country's oldest ally. That will not go down well in Downing Street or the Foreign Office. In publishing a "substantial body of evidence" to implicate the Syrian government in attacks Mr Kerry said killed nearly 1500 people, the momentum towards American intervention in Syria has clearly intensified. The Commons vote, while in some ways defining, does not rule out British involvement in the future. But it will require harder evidence, UN backing and a second vote to justify British involvement. Previous conflicts have shown the danger of the UK becoming enmeshed in complex international conflicts without a clear idea of what is achievable, how it is to be achieved and what the endgame is to be.