The decision to go to war is the most onerous one which faces an MP. Lives, often innocent lives, will be lost, so the reasons have to be strong, based on evidence and have clear outcomes and positive consequences. The reasons to go to war do not include "because I'm angry", "because people expect it", "because we'll be the odd one out if we don't" or least of all "because I want to put down a marker in some internal dispute".
The British Parliament has already made a vital contribution to the process, two years ago refusing to bomb Assad which would have cleared the way to the Mediterranean for Islamic State. It was a vote which gave backbone to the US Congress. Now Parliament, by delaying the rush to war has done a further great service by winning vital thinking time. This has enabled all of us, especially Government, to better comprehend the incredibly complex, multi-dimensional nature and history of the regional conflict.
Parliamentary debate has enabled all of us, regardless of party or creed, to see more of what unites all of us-how best to defeat Islamic State on a sustainable basis.
The evil of Islamic State must be beaten, their cruelty plumbs new depths of inhumanity and immorality, self-justified by perverted religious fundamentalism. To defeat them cannot happen on the battlefield alone. To do that we need to be smart and not repeat the mistakes of the past. There was no Islamic State in 2003, it has evolved from the ashes of Iraq. Despite the biggest rebellion within a Governing party in British political history, the UK and other foreign armies invaded Iraq. This war opened up the Pandora's Box of religious fundamentalism. Failure to have a strategy for the peace or for exiting the war led to regional instability, financial and political corruption and a level of dysfunction which, even if we get everything right from now on, will blight the Middle East for at least a generation. We have to stop being in denial that our military intervention in Iraq, Libya and Afghanistan has not made things worse. It was exactly what Islamic State would have wanted us to do. First of all, we must stop being a recruiting agent for Islamic State.
The perfect breeding ground for terrorism was created in the devastated populations, broken communities, eradicated infrastructure and a million orphans looking for a cause.
To throw into the mix a tiny UK air force (of perhaps no more than five jets) will only inflame the incendiary cocktail of religious, ethnic and sectarian violence and civil war that has been unleashed in the region. There are already call for UK troops on the ground and we know from Afghanistan and Iraq that without a clear strategy, the military and politicians rapidly succumb to "mission creep" not least when surprised by unconventional warfare waged by a fanatical enemy. Attacking another country and taking [including large numbers of civilian] lives without an internationally agreed plan of what we wish to achieve, how - even if we were successful - we would fill the institutional, political and religious vacuum, how we would build a lasting peace and what our exit strategy should be, would be to rerun and amplify the mistakes we have made in the last decade in the region.
We need to understand our enemy and isolate them from mainstream Muslim opinion using the intelligence and statecraft for which we were once famous.
The UK Government, like the ones before it, is only now being forced by MPs and the Foreign Affairs Select Committee to think about these issues and being made to write out a plan which goes beyond the tactical. No doubt this dossier will be more convincing than some of the dodgy ones that have preceded it. However, a glossy brochure which gets us by and gives cover to those who need it is not enough.
The real answers are uncomfortably long-term, above all supporting the reformation of Islam with as much soft power as the world can muster so that the fundamentalists can be rejected by Muslims everywhere. In the immediate there is a massive political work programme for those who reject a military quick fix. We need to develop, protect and extend safe havens. We must work - however unpalatable it may be - with Assad, Iran and Putin. We need to build an Arab coalition of Middle Eastern forces perhaps with United Nations auspices to rebuild and police shattered societies. We need to confront and hold to account the Saudi funders of Islamic State. We must cut off forever the free-flowing oil money from Northern Iraq which feeds Islamic State. We need to help convene a standing peace conference to re-draw the imperial map of the region. There are many other strategic issues that need to be resolved, each of which is a harder longer road than deploying five aircraft.
While our first understandable reaction to any atrocity will always be to "do something", it is vital that we do the right thing. MPs above all need to take pride in what we have contributed so far, use a cool head and help Government to see a clear long term strategy. If we don't meet our responsibilities, the cycle of killing and the fear it brings become a permanent fixture in our and our children's lives.
Graham Allen is MP for Nottingham North and one of the organisers of the votes against the UK war in Iraq 2003