Armed Conflict (Parliamentary Approval)

Does my hon. Friend agree that scaling back the Crown prerogative by ensuring that parliamentary approval was required before engaging in armed conflicts would help to clarify our war aims from the outset? Clear, unequivocal war aims would ensure that we avoid the sort of mission creep that is taking place in Afghanistan, where a war that started to root out the Taliban is fast becoming a counter-productive campaign to eradicate poppies. Does my hon. Friend agree that, regardless of which party is in office, rolling back Crown prerogative would mean better decision making, greater clarity and less muddle?