Must MPs always vote before we go to war?

Jesse Norman was permitted three minutes for his speech to the Commons in last Friday’s debate. But the contribution from the Conservative MP for Hereford & South Herefordshire was one of the more important backbench interventions — and no less important for being wide of the debate’s focus.
The House was being invited to support British intervention against the Islamic State. Mr Norman’s speech was about whether the invitation was even appropriate. As he put it, ‘A convention has started to develop that, except in an emergency, major foreign policy interventions must be pre-approved by a vote in Parliament.’ The MP thought this unwise.

I disagree. Or half-disagree. But ­Norman’s case was powerful, and I shall give you the gist. He is all in favour of debates, questions or statements on military action; he thinks them vital; but he objects to the emerging rule that ‘a prior authorising vote’ should be required. ‘The plain fact is,’ he said, that in matters like this, ‘members of the House are inevitably far less well informed than ministers who follow and reflect on the issues every day.