David Cameron made a gross error of political judgment by recalling parliament and asking MPs to agree to support military action in principle when both the factual evidence and the legal position were still so unclear. He should have waited. He should and could have built a political consensus. Instead he tried to rush the matter through to suit the US's timetable.
It is astonishing that the Coalition did not realise that they might well lose the vote. The result should not have come as a surprise. After all, MPs can be expected to take public opinion seriously and furthermore some 80 Tory MPs signalled at the start of the summer that they wanted parliament recalled before any action in Syria, a clear indication that they might be opposed.
Parliament did its job last night. It held the government to account. Cameron failed to make his case.
Last night's vote is the first time in centuries that a British PM has been stopped from carrying out military action by parliament. It is also the first time for many decades - since Harold Wilson kept the UK out of Vietnam - that Britain has not fallen in with the military agenda of the US.
Short of a vote of confidence this is the most important possible vote that Cameron could lose. His loss of authority is immense. His leadership could even be threatened.
Below is Miliband's email.