A year ago MPs debated the most important question parliament can ever be asked, and the most difficult decision an elected representative can make: whether our armed forces should be deployed to defend our national interests. We decided that British air power should be used to support the Iraqi Government against the terror group which styles itself "Islamic State" (IS). My colleague, the Labour MP Clive Lewis, has recently suggested that MPs would be less keen to send our troops into battle if they knew the true realities of war. It is an understandable view and a point often made to those of us who have advocated intervention.
But there can be devastating consequences of inaction too. Our willingness to risk the lives of our servicemen and women is fundamental to deterring those who seek to violate international principles we have sought to uphold for the past 75 years. Since parliament vetoed action against the brutal Assad regime following his chemical weapons attack in 2013, 220,000 people have been killed and a staggering 50 per cent of the population has been displaced. This is an unfolding tragedy that is, figuratively and literally, washing up on our shores.
It is time to debunk the myths that everyone was as bad as each other in Syria and that, by intervening now, we can only make things even worse. In fact, failure to take action in 2013 against Bashar Assad once he crossed the red line of using chemical weapons against his own people emboldened him to step up his campaign against defenceless civilians. It encouraged his Iranian and Russian supporters and it rallied the extremists of IS to believe they could roll across the Syrian border into Iraq without being wiped out.
David Cameron's ineptitude in failing properly to make the case and persuade parliament to endorse military strikes in response, and Labour's decision to oppose the vote, are two of the principal triggers of today's refugee crisis. With the Syrian people left to fend for themselves against the brutality of Assad and IS, and with no end to the conflict in sight, it is no surprise that so many are fleeing the country.
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The only way to end the crisis and stop millions more Syrians fleeing is for other nations to play what role they can in making their homeland safe. The question is how.
Progress has been made against IS in Iraq in the last year. Key parts of the extremists' regime have been destroyed with very few civilian casualties and fighters have been pushed back in many key strategic areas of Iraq. But no matter the spin, the reality remains that the slow and tentative support to the moderate opposition has left only a handful of US-trained Syrians taking the fight to IS. It is a fight they cannot win on their own.
Meanwhile, the humanitarian crisis has continued to grow into a tidal wave of despair and suffering, with no end in sight.
There is no argument from those of us who have advocated action to put British boots on the ground. That would place a disproportionate burden on us at a time when Syria's Arab neighbours need to take the lead, and be counter-productive in the longer term struggle of winning the hearts and minds of communities which are too often seeing the extremists as protectors rather than invaders.
But the Royal Air Force can and should play a greater role, extending air strikes over the practically non-existent Iraq border to hit IS targets in Syria and, crucially, protecting civilians with no fly zones from Assad's barrel bombs.
Establishing a no-fly zone would help establish safe havens in the country, allowing civil society to get back on its feet and giving terrified families confidence to stay in their homes rather than flee.
It would also play an essential part in showing Russia, which continues to finance Assad and is moving its own troops towards Syria, that those countries being affected by the refugee crisis have the resolve to face down its intimidation and create the necessary climate for the political settlement which must eventually come.
No one is pretending such actions would be a panacea for the overwhelming political, sectarian and tribal complexities of the region. An end to the turmoil in the Middle East and defeat of the twisted ideology that IS champions can only be achieved through non-military measures in which Britain can, at best, play only a supporting role.
But this limited military intervention from Britain as part of the international coalition against IS could serve as a protective umbrella under which those who are better placed to change the conditions on the ground could flourish.
It is time for the prime minister to show leadership and a greater sense of grip than he has in recent years. And it is time for parliamentarians on all sides of the house to reconsider the prospect of greater military intervention with an open mind.
This conflict will scar the region for generations and have a lasting impact on Britain whatever happens. But the sobering truth is that the course of action or inaction which the UK and other nations choose now will determine how many generations will endure this catastrophe. It is a choice on which parliament should be asked to decide, and soon.
