A day for clarity on Syria from the Prime Minister It is impossible to approach the debate in Parliament about intervention in Syria without recalling the day in March 2003 when Tony Blair set out his arguments for attacking Iraq. This newspaper described his performance as one of the finest in recent Commons history: he marshalled a moral, legal, geopolitical and humanitarian case with such conviction that a Labour rebellion was contained and a large majority secured. Public opinion also swung marginally in favour of invasion. David Cameron is also a noted parliamentary performer, especially at moments of crisis, and we would expect nothing less than a polished and persuasive speech. Yet the fact that so few people - less than 10 per cent of voters, according to one poll - support a strike against Syria owes much to the deep scepticism that the Iraq war engendered. After Labour put forward an amendment demanding that UN inspectors be allowed to finish their work, the Government accepted that any "direct British involvement" in military action will depend on a second vote of the House of Commons, after the inspectors deliver their report. This was attributed to the "deep concerns" that the public have in the wake of Iraq, with its baleful legacy of dodgy dossiers, inadequate planning and misplaced triumphalism. Still, Ed Miliband will doubtless claim a tactical victory. Yet the postponement actually rescues him from an ugly hole, given that his party's policy has been one of incoherent prevarication. As for Mr Cameron, the resolution makes clear that the Government is still marching down the road to military intervention, if at a slightly slower pace. But if he is to win over a sceptical public, he must offer absolute clarity about the basis for this proposed action and its intended consequences. We are assured, for example, that any military strike will be solely in retribution for Bashar al-Assad's apparent use of chemical weapons against his own people, rather than being intended to influence the outcome of the Syrian civil war. Yet we were told that the Libyan intervention in 2011 was not about toppling Col Gaddafi, even though that is precisely what happened - one reason why Russia is so suspicious of Western motives now. We also need to be told as much as possible about the intelligence showing that the gas was deployed by Assad's forces, not by the rebels - and to see the advice that Dominic Grieve, the Attorney-General, will have given to the Cabinet containing the legal basis for action, in the absence of a UN resolution. With the ghosts of Iraq hovering at the Prime Minister's elbow, his case must be made not just with conviction, but complete transparency.