12.12am BST

Already some commentators are saying that this is a rare example of a Commons vote that is genuinely historic, one with serious repercussions that will reverberate for years. (See 10.55pm.) Trying to sum up the consequences when the division lists are still be written up is bound to be a flawed exercise, but here are some initial thoughts on what it means.

1. Britain will not be attacking Syria. MoD chiefs can pack away their maps of Damascus, and the submarine commanders will turn around. (At the very least, with cruise missiles at £500,000 a shot, the MoD will save a few quid.)

2. The "special relationship" has just become less special. One reasons links between Washington and London have generally been so close is that they could generally rely upon us in a fight. Now they can't. And that might be because ...

3. Britain is becoming less imperialist, and more European. This is probably the most important lesson to be learnt from tonight's vote. In the past prime ministers have justified interventionist policies on the grounds that Britain is an outward-looking power that gets involved in the world, that tends to gets "stuck in". This is normally explained as a legacy of our imperial past. But the public seem to have had enough. Any more wars? No thanks. We're turning German. And that affects what the government does because ...

4. Parliament matters more. Technically prime ministers do not need the support of the Commons to go to war. Sending troops into action is a prerogative power (meaning it can happen just on the prime minister's say so). But Tony Blair allowed a vote on the Iraq war, and since then parliament has been flexing its muscles even more. Of course having a hung parliament helps. But this might be a good night to remember Robin Cook, whose gravestone carries the words: "I may not have succeeded in halting the war, but I did secure the right of parliament to decide on war." The Tory MEP Daniel Hannan put the point about parliament's new assertiveness well in a blog written after Cameron's U-turn on the motion last night.

In fact, something bigger has taken place: the legislature has exerted itself against the executive. In opposition, to his credit, David Cameron promised that he would consult Parliament about war-and-peace decisions. He has been as good as his word. MPs, not unnaturally, reflected their constituents’ views, and it became clear that there was no appetite for an immediate strike against Syria. The system, you might say, worked.

5. Ed Miliband has pulled off one of the most accomplished come-backs in recent political history. All summer he endured comments from the media, and Labour MPs, suggesting he should be doing a bit better. Now he has stopped a bombing campaign. Cameron lost the vote because he failed to persuade enough Tory MPs to support him, but Miliband pushed Cameron hard, and (even if, like me, you think his speech was a bit of a fudge) he deserves to take some credit for Cameron's defeat. It is fashionable to deride Miliband as ineffective, but now he can rightly say that he is the first Labour leader to pick fights with the both News International (over phone hacking) and the White House (over Syria) and win.

6. Cameron is not going to resign, but his authority is badly damaged. To be fair, Tory MPs who said they had doubts about Cameron's strategy in the debate did not criticise him in personal terms. But he has been pushing for a robust response to Syria, he decided to recall parliament and he opened the debate. For a prime minister to lose a vote on a major foreign policy issue like this is unprecedented in modern times. He is a weaker figure than he was a week ago.

7. The forthcoming government reshuffle may be wider than expected. At the very least, Cameron may conclude that he needs a new chief whip (although we don't know whether Sir George Young was really to blame, or whether Cameron ignored his advice.)

8. Tony Blair remains one of the dominant figures in British politics. The last time parliament was recalled it was to allow MPs and peers to pay tribute to Lady Thatcher. Today’s debate was similar in that another former prime minister dominated the proceedings in his absence, with Cameron saying he was determined not to follow the template Blair laid down for the Iraq war, but at the same time advocating classic Blairite liberal interventionism. MPs rejected it. Afterwards Philip Hammond suggested Blair was to blame for the government losing, because he "poisoned" public debate over Iraq. (See 11pm.)

That's all from me for tonight.

Thanks for the comments.