"Fool me once, shame on you; fool me twice, shame on me" - so the British Parliament decided it didn't want to be shamed by following another prime minister into another unwinnable war on the basis, yet again, of shoddy intelligence.
It voted 282-275 against committing British forces to the planned American attack on Syria. After the vote on August 29, Prime Minister David Cameron admitted that former prime minister Tony Blair had "poisoned the well" by leading Britain into the Iraq war in 2003 on the basis of false intelligence reports about Iraq's non-existent "weapons of mass destruction". That was why neither the public nor even some members of Cameron's own party now trusted his assertions on Syrian "WMD".
The next day, US President Barack Obama followed the British government's example by announcing that he would seek the approval of Congress before launching strikes on Syria. He still felt that the Syrian regime should be punished for using poison gas, he said, but it turns out that the operation is not "time-sensitive" and can wait until the US Congress resumes sitting on September 9.
Obama is probably secretly grateful to Britain for pulling out, because it has given him an excuse to postpone the attack - maybe even to cancel it. He foolishly painted himself into a corner last year by talking about a "red line" that he would never allow the Assad regime in Syria to cross, but he wasn't elected to be policeman of the world.
That was the role George W Bush tried to play, but American voters want no more of the wars that come with it. Obama got US troops out of Iraq, and they'll soon be out of Afghanistan as well. He doesn't want to end up fighting a war in Syria, and that will be hard to avoid that if he starts bombing.