Last week I listened carefully to the Prime Minister make his case for why the UK should join the bombing campaign against Isis. The debate in the House of Commons was thorough, and the horror and revulsion at recent atrocities in Syria, Paris, Beirut and elsewhere is shared by MPs from across the political divide.
Yet I have still to see any evidence to suggest that UK bombing Isis targets in Syria is likely to increase our security here in Britain or help bring about a lasting peace in the region in question - to the contrary, the evidence appears to suggest it would make matters worse.
The airstrikes on Syria have become increasingly Western driven, with all of the four Middle Eastern states previously involved - Jordan, Bahrain, Saudi Arabia and the UAE - now having withdrawn. ISIS attempts to present itself as the true guardian of Islam under attack from the 'crusader West'. This message, though utterly pernicious and wrong, is being reinforced by Western bombings, with every indication that the attacks are an incredibly effective recruiting sergeant for Isis. According to US intelligence sources, in September 2014, 15,000 recruits were reported to have joined from 80 countries; a year later the figure had risen to 30,000 from 100 countries. The Prime Minister couldn't give any assurances that western military action wouldn't drive more recruits to Isis.
Nor have the sustained bombings pushed Isis into retreat. According to the latest figures from the US Department for Defense, the US air war has so far killed an estimated 20,000 Isis supporters, yet the number of fighters they can deploy - between 20-30,000 - remains unchanged.
Crucially, though, British military involvement in air strikes may well hamper our ability to push for diplomatic solutions. Evidence given to the Foreign Affairs Select Committee by Julien Barnes-Dacey, a senior policy fellow at the European Council for Foreign Relations, suggests that intervention is likely to undermine our political and diplomatic role, whilst offering 'nothing meaningful in terms of military numbers'. The Committee Chair also put paid to the idea that our involvement is critical, saying, just over a week ago, that "there is no great military necessity for the UK to be involved since planes are queuing up from a wide range of countries over the skies of Syria".
With Russia and the US already dropping bombs on Isis in Syria, it is clear that there is no shortage of firepower in the region, but after such heavy bombardment there is a distinct lack of clear remaining targets. This is compounded by Isis' deeply cruel use of 'human shields', which will both make targeting them more difficult and add to the civilian death toll.
It's concerning too that the Prime Minister has failed to demonstrate anything other than wishful thinking when it comes to the essential ground forces which would be necessary. His claim that there are 70,000 moderate forces which could move into the region and oppose Isis is highly disputed. It's worth repeating - for the sake of the many MPs with short memories - that it was only two years ago that the Prime Minister's plans for bombing Syria had the Assad forces who are currently fighting Isis as their target. Those very forces are widely acknowledged to have murdered many more civilians than Isis, yet in effect we're planning to aid them by bombing their enemy. Government claims of having a comprehensive long-term strategy for a Syria free from both Isis and Assad simply don't stack up.
Nor has Cameron successfully answered crucial questions about the damaging role of Britain's ally Turkey in the region. Without applying diplomatic pressure to the Turkish Government to end persecution of the Kurds, the chances of ending the civil war in Syria remain remote.
It's critical that the burning desire to act, to stop terrorists and keep us all safe, doesn't result in an approach that ignores the evidence of our recent interventions in the region - or their consequences. The civilian death count from the Iraq war and its aftermath is at least 147,000 and, according to Barack Obama, the resulting instability laid the ground for the rise of Isis. Post-Gadaffi Libya, which also has British fingerprints all over it, is witnessing Isis forces gaining power too. Isis thrives in the chaos brought about by Western intervention, which is why the unintended consequences of the 'War on Terror' must serve as a stark warning to anyone thinking of supporting airstrikes in Syria.
But let's be clear: the choice we're facing is not between military intervention and inaction. The Government can and should play a role in brokering peace and stability in the region. The Prime Minister could start by redoubling his commendable efforts to find an urgent diplomatic solution. Given that Isis flourishes where chaos reigns, renewed effort needs to be made to end the Syrian civil war The talks in Vienna are a start, but the process must be accelerated and continue to involve all proxies to the war. That diplomatic effort must also extend to Iraq, where the Abadi Government must be encouraged to reach out to the neglected Sunni minority - especially in those parts of the country where Isis is recruiting.
The British Government should also immediately suspend British arms sales to the Middle East and commit to a foreign policy that is consistent as well as ethical, particularly when it comes to our relations with countries that undermine human rights.
Furthermore Britain must both firmly abide by and improve upon its current commitment to taking in Syrian refugees. With winter approaching, there's a clear humanitarian imperative, but Ministers must also wake up to the very real risk that increasing poverty and desperation could lead refugee camps in Jordan, Lebanon and Turkey to become recruiting grounds for Isis too.
This is not 2003 and the Government appears to have made its case in good faith. It is now down to MPs to examine both the evidence and their consciences before deciding how Britain should act. Barely a month ago, the Foreign Affairs Committee concluded that "the focus on the extension of airstrikes against ISIL in Syria is a distraction from the much bigger and more important task of finding a resolution to the conflict in Syria and thereby removing one of the main facilitators of ISIL's rise." I can see nothing that has changed since then. That's why I intend to vote against this military action in Syria - and will be urging the Government to wage peace rather than war by pursuing non-military means of bringing about an end to this most intransigent of conflicts.
Caroline Lucas is the Green Party MP for Brighton