The Syrian Civil War is now the great global crisis of our time. What began as a civilian uprising against the brutality of the Assad regime quickly became a bloody, complex civil war that shows no sign of abating. So far the conflict has claimed over a quarter of a million lives, drawn in a range of states in the region as well as the two Cold War superpowers, and caused a humanitarian crisis that has spilled over into both neighbouring countries and now the heart of Europe.
No-one with an either ounce of humanity or a concern to prevent further escalation of an increasingly dangerous conflict can say this is none of our business. And with a political solution seemingly so distant, it is unsurprising that the option of direct UK military intervention has returned to national political debate.
The lead option - and the one that the government looks likely to ask for Parliament to approve some time soon - is for the UK to join military activities against ISIL in Syria. The case is made most forcefully by our defence secretary Michael Fallon. ISIL, he argued to Andrew Marr on Sunday, "is run from North East Syria [and] is a direct threat to people here in the UK". It has beheaded British citizens, and is responsible for the brutal murder of over 30 British tourists in Tunisia. Parliament has authorised military action against ISIL in Iraq, yet ISIL operates across the Iraq-Syria border in ways that make it difficult to justify attacking them in Iraq and not join existing American-led military action in Syria. Fallon is careful not to pre-empt a Parliamentary vote, but his position and argument are admirably clear.
The vast majority of British citizens share a desire to rid the world of ISIL and to protect both Syrian civilians and future targets of ISIL atrocities elsewhere. Yet the desire that "something must be done" is a long way from winning the argument about a particular course of military action as a way to do it. And we also have a duty to avoid making a terrible situation worse. The Commons debate of the Fallon proposal will examine the case for attacking ISIL on a range of legal, military and strategic grounds. When it does so, I believe it should reject it.
Let's start with arguments that cannot justify the Fallon proposal for military action. The case for attacking ISIL on humanitarian grounds is weak: not because ISIL is not guilty of horrific attacks on civilians, but because responsibility for the vast majority of civilian casualties in the Syrian civil war lies not with ISIL but with President Assad. The Syrian Network for Human Rights judged that from January to July 2015 Assad's forces were responsible for seven times more casualties than ISIL. It is estimated that last year around 88% of those murdered by pro-Assad forces were civilians: nearly a quarter were women and children. Atrocities continue to be committed on all sides in this gruesome conflict, but if protecting civilians is the goal then military action should be focused primarily on stopping Assad.
It is also clear that the same justification in international law that supported UK intervention against ISIL in Iraq cannot be used to justify intervention in Syria. In Iraq we acted with the consent of the Iraqi government. No such justification is available in the case of Syria. Of course, strikes against ISIL, the government's most powerful opponent in a complex civil war, benefit the Assad regime, and for that reason they have not interfered with US operations against ISIL so far. But no one either can or wants to make the case for UK military action against ISIL on the basis of consent from the brutal Assad.
Other justifications are available under international law. UN Security Council authorisation can allow the UN Charter's prohibition on the use of force in another state's territory to be overridden. But no such authorisation has happened, nor is likely in the near future.
Which leaves justifications based on self-defence. Here there is a discrepancy between the argument made by the United States when it began operations in Syria, and the Fallon Proposal for UK action. The US case to the UN, set out in a letter to the Secretary General on 23 Sep 2014, justified American military engagement in terms of protecting the security of neighbouring Iraq. It argued that Assad's unwillingness or inability to wipe out safe havens in Syria used by ISIL to launch attacks against Iraq triggered their right to self-defence under Article 51 of the UN Charter. As American assistance to the Iraqi regime was based on the latter's consent, this justified US military action against ISIL in Syria on the grounds of collective self-defence.
Expert legal opinion is divided on whether the American rationale based on collective self-defence stands up. But Fallon's argument about intervention is different and legally much more flimsy. His case is based on the threat not to the territorial integrity of Iraq, but to the UK directly. There is no doubt that atrocious crimes have been committed by ISIL against citizens of other countries, including British citizens. But as the international law experts Louise Arimatsu and Michael Schmitt recently argued, "in international law an armed attack implies more than isolated criminal acts against a state's citizens, however brutal". It is very difficult to argue that ISIL is attacking the UK in such a way as to justify our Article 51 right to territorial self-defence. And, given what we know, it is equally hard to see how Fallon could argue there was an imminent threat to the UK that required anticipatory self-defence.
Some say that the niceties of international law are neither here nor there when it comes to matters of security. I strongly disagree. If we expect to be protected from the aggression of other states, and to use international law as a weapon against states that violate it, we would be foolish to dismiss it. For a host of moral, political and historical reasons, Britain should be not be embarking on any course of military action that fails to meet the tests of international law.
Fallon's proposal is hard to justify under international law. But putting aside the legality of military action against ISIL in Syria, would such action be effective and wise?
The wisdom of military action is ultimately based on the wisdom of the overall strategy on which that action is based. Yet the American strategy for attacking ISIL is currently in need of a fundamental rethink. An aide to John Kerry recently described the US approach as a three-part strategy: "degrading IS through the bombing campaign, training the armed opposition and trying to get something going politically". Of these three strands, the third remains as remote a prospect as it has done throughout the Civil War. The second (training the armed opposition) has just been abandoned by the US after spending $500million to train a meagre total of about 60 fighters. The approach of training rebel forces to fight against ISIL has run up against the formidable obstacle that rebel fighters see Assad, not ISIL, as their primary enemy. And there have been incidents of American-trained fighters giving some of their US-provided equipment to the Nusra Front, an affiliate of Al Qaeda.
Meanwhile, although the bombing campaign has had some successes (particularly around Raqaa) it is highly unlikely that it will result in the defeat of ISIS. ISIL is not a state and does not have the asset infrastructure that normal states possess. Attacks on ISIL's oil refineries have had some effect, but ISIL has got better and better at rebuilding them. Its fighters are now well-practised in going to ground to avoid the destructive effect of air attack, and it has learnt not to send its tanks and armoured personnel carriers out in the open. As Syrian civilians, Kurdish fighters and military analysts concede, air strikes can only take out a limited number of high-value targets. If the mission of air strikes is to "degrade and destroy" ISIL's assets and forces, you would be hard pushed to find many - in Syria or observing from outside - who think the strategy is working.
It would be short-sighted to contribute UK military forces to a campaign whose strategy is at best questionable and at worst simply not working. But the strategic problem of military intervention against ISIL goes much deeper than that.
Michael Fallon's case for attacking ISIL at times seems to abstract from the fact that Syria is immersed in a civil war. He wants Britain, alongside the broader international alliance, to fight ISIL, and for other rebel forces to take up that fight too. But this is a plan for military intervention that imagines lines of conflict that are totally different to those on the ground. Syria is in the middle of a complex, brutal civil war. Rebel groups are risking their lives to rid Syria of Assad, no matter what we would like them to prioritise (hence the acknowledged failure of the American strategy to arm some rebel forces).
Most importantly, advocates of military action against ISIL in Syria need to face up to a fundamental bit of realpolitik: whether we like it or not, UK intervention to attack ISIL helps Assad's fight in the Syrian Civil War. We acknowledge this zero-sum logic in the case of Iraq, where we are trying to assist the Iraqi government by defeating ISIL. The fact that we despise Assad's regime does not make the same logic less true in Syria. And any strategy that is in denial about such a fundamental effect of intervention is not a good basis on which to intervene.
Of course Michael Fallon maintains that attacking ISIL does not equate to supporting Assad, and that ultimately the only solution acceptable is one in which both ISIL is defeated and Assad is gone. But this is an asymmetrical strategy: responding to the evils of ISIL with military action, and responding to the evils of Assad with exhortation to step down. To be opposed to both ISIL and Assad but only will the means to defeat ISIL is to give a military advantage to Assad. At the very least, the case for military action against ISIL has to set out what the next steps would be if the action succeeded, in order to stop Assad benefiting from the retreat of ISIL. But it is difficult to see what that action would be short of a wholly implausible scenario of further military engagement against Assad (and his allies, including and especially Russia) combined with continuing the fight against ISIL.
Perhaps most fundamentally of all, it is surely folly to intervene in the Syrian civil war without a conception, let alone a plan, for what peace in Syria might look like. If international action succeeded in defeating ISIS, would we then withdraw our forces to let the civil war continue? Military intervention to bring about a cessation of violence in Syria is beset by a formidable range of legal, military and political problems, but in principle it would have the widely-accepted doctrine of the Responsibility to Protect on its side. But military intervention in Syria that does not aim to bring this most brutal of civil wars to an end seems indefensible, and is almost certainly not going to be supported by the Syrian people. And, in the absence of some kind of plan for peace consistently supported by a majority of the international community, it is more likely than not to increase rather reduce the chaos.
Where does that leave those who feel revulsion and horror at the continuing barbarism of both ISIL and Assad?
First and foremost, it points us towards a more comprehensive approach to humanitarian relief for Syrian refugees. Britain is a leading player in supporting humanitarian support for the victims of Syria who now live in neighbouring states. But as Jo Cox and Andrew Mitchell argued recently, it is now imperative that the collective international effort is stepped up -to support reconstruction of the neighbourhood; provide more systematic support for the welfare and education of displaced Syrians living in Lebanon, Jordan and Turkey; strengthening search and rescue operations in the Mediterranean; and providing safe and legal routes to apply for asylum.
Second, if we want a lasting solution to the Syrian crisis we are going to have to make some unpalatable choices about the alliances we make to help get there. In particular, a future Syria with neither ISIL nor Assad cannot come about without a strategy coordinated with Russia and Iran. Russian military intervention on behalf of Assad was cynical and escalatory, and has made the possibility of a political settlement seem even more remote. Yet their and Iranian involvement in a plan for bringing an end to the civil war is essential, no matter how remote a prospect that seems at present.
Defeating ISIL in Syria requires the support of a Syrian people and diverse Syrian rebel groups that see Assad as their common enemy. A pre-requisite for a coordinated strategy to rout ISIL is therefore a coordinated plan for a post-conflict Syria - one which uses constitutional imagination to find a place and protection for different ethnic and religious groups, and which offers the prospect of replacing Assad at the helm. Travelling the long distance to that coordination - not just with Russia and Iran but with other states in the region - is the essential diplomatic challenge for Britain in the months ahead. Philip Hammond took a brave decision to reopen our Embassy in Iran and restart our diplomatic relations with Tehran. The next task is to being to engage with senior figures in Iran over Syria. Similarly, we should develop (perhaps with European partners) a regional diplomatic plan of engagement with Gulf states with whom we have better relations, to encourage them to direct their activities towards ending the conflict and think collectively about what comes next.
All this may seem partly distasteful and partly fantasy diplomacy given the situation Syria currently faces. But if the alternative is UK military action that is not grounded in international law, based on a flawed military strategy, and in denial of the fundamental contours of the conflict, it may be the best of a truly grim set of options.
Lord Stewart Wood is a Labour peer and former Cabinet minister