British Prime Minister David Cameron was defeated Thursday night on a vote which was intended to authorise the bombing of Syria. The Labour Party voted against him. But, even more strikingly, so did 30 of his own MPs. And Britain is buzzing about it. It may all seem quite remote from Jamaica and its immediate economic challenges. But it will have international repercussions.

One person with a headache is American President Barack Obama. He was reluctant to take military action in Syria, but came under pressure (on this as on so many other things) from right-wing Republicans. He also made the mistake of saying that the use of chemical weapons in Syria would be his “red line” which would force him to intervene militarily.

Lo and behold, someone has now used chemical weapons, although it is not clear whether it is the homicidal Syrian leader Assad himself, or his opponents seeking to get America involved. Obama was assuming that he would have British support for air strikes against Syria. Now the British Parliament has crushed that possibility. It remains to be seen whether Obama will go ahead on his own or use British parliamentary opposition as an excuse to back off military action.

But losing this vote has also made PM Cameron look incredibly weak. MPs were all called back from our holidays for a special session of Parliament. Cameron assumed that MPs would vote for war. It turns out that he completely miscalculated and has been defeated. Part of Cameron’s problem is that much of his party don’t like him and were glad for the opportunity to rebel.

No British prime minister has been defeated on a foreign policy issue in the House of Commons for centuries. It reveals that Cameron is completely out of touch with his party and cannot manage it effectively. Losing this vote calls into question his ability to deliver on a range of issues, not just foreign policy.

But the vote is very good news for Labour leader Ed Miliband. He has been derided for months as weak, ineffectual and leading Labour to defeat. Now he has completely out-manoeuvred Cameron and delivered a crushing parliamentary defeat. Losing the Syria vote may be a turning point for Cameron. In retrospect it may be seen as the point when Ed Miliband secured victory at the next general election.

The vote may also mark the point when the British Parliament accepted that it has to start giving up its post-imperialist pretensions and stop playing Robin to America’s Batman. If so, it would be a good thing. It’s long past time that Britain stopped thinking it could be a world policeman alongside America.

This vote against war with Syria is also a boost for the powers of Parliament, as opposed to rule by the dikta of a Prime Minister. Parliamentarians everywhere should take heart from it.

Diane Abbott is a British Labour party MP and spokeswoman on public health

www.dianeabbott.org.uk