As ever, the Syrian regime gives with one hand and takes with the other. On Sunday, Damascus allowed UN weapons inspectors to gather evidence at the site of an alleged chemical gas attack in al-Ghouta. Saudi-backed terrorists were responsible for the atrocity, state media told a sceptical world. Yet only days later, a BBC news team reported from the scene of an horrific incendiary attack by government fighter jets against a school playground in Aleppo.

Though the UK has bowed out of a possible punitive strike for the use of chemical weapons at al-Ghouta, it seems that the US may proceed with other, as yet unnamed, allies. US destroyers have moved closer to Syria in recent days, and would likely launch cruise missiles against targets associated with the regime's chemical weapons capability.

The narrow context of chemical weapons use allows the Obama administration to focus, and therefore limit, its military involvement in Syria. The US response can be tailored to, and circumscribed by, the incident - "a bout of therapeutic bombing", as Eliot Cohen put it in The Washington Post. Still, however limited, the proposed action is dogged by questions of strategy and legality.

It is not immediately clear what limited air strikes against select regime targets would achieve. The unbearable suffering of the Syrian people is often cited as the basis upon which military action must take place, but how will the humanitarian situation be ameliorated by the strikes? In fact, US military action could lead directly to civilian casualties and the displacement of more families from their homes, and indirectly to further massacres and atrocities, should the regime, and its erstwhile Iranian allies, take retaliatory measures.

In addition, US military involvement could further mutate the Syrian conflict, reigniting the regional anti-American and anti-imperialist fires that had only recently begun to die down, a decade after the Iraq invasion.

The legal grounds for the strikes are also shaky, given that Syria is not a signatory to any of the relevant treaties proscribing the use of chemical weapons. While Syria is a party to the Geneva Gas Protocol of 1925, its stipulations regulate only the conduct of war between states. At the same time, a two-year stalemate on the United Nations Security Council precludes the possibility of obtaining a Chapter VII mandate, as occurred with Libya. Within the US itself, there is a legitimate debate over whether the president can legally engage in an act of war without the Congressional approval he has said he will now seek.

Proponents of the strike have a strong, emotionally charged argument in their favour: the crimes of Bashar al-Assad's regime shock the conscience and must be stopped. Those against the proposed action brandish an equally compelling headline: the Iraq war exposed the grave dangers of combining imperial hubris with hypocrisy - didn’t US troops use white phosphorous and Mark-77 napalm bombs in Iraq?

Indeed, when the welfare of the Syrian people is the main consideration, there are no easy answers. The continuation of the brutal regime in Damascus will undoubtedly lead to more crimes and widespread human rights violations, but so will regime collapse. This painful conundrum, which lies at the heart of the Syrian crisis, paralyses even those with the best of intentions.

In his address to the British parliament, Prime Minister David Cameron emphasised that military action was not about taking sides, regime change or invasion, but rather about responding to a war crime. To be sure, the use of chemical agents against thousands of unarmed civilians, including children, is a crime against humanity. Yet dozens of other war crimes have been reported in Syria involving conventional weaponry, against adults and children alike, including summary executions, torture, and beheadings.

Throughout Syria, the civilian population has been deliberately targeted with everything from "barrel bombs" to suicide bombs. In those places, the affront to human dignity was as intolerable as at al-Ghouta, the deaths as terrible.

One of the main moral impulses behind the revulsion over chemical weapons is that they do not discriminate between the combatant and the human being - in the words of Thomas Nagel, they harm the man and not the soldier. Chemical weapons are especially bad because they are designed to maim or torture the soldier, rather than merely stop him. But the victims of the conflict in Syria are rarely soldiers, rendering redundant the distinction between conventional and chemical weaponry upon which western governments are currently relying. By all moral codes and international legal norms, the deliberate killing of civilians is a war crime, no matter the weapon used.

In this wider context, the use of chemical weapons as a trigger for action in Syria seems morally and legally arbitrary. At the same time, responding only to the chemical weapons dimension promises to leave the fundamental dynamics behind the horrific cycles of violence untouched.

Western leaders are right to argue that the international community cannot turn away from what is happening in Syria today. However, any response must be directed at the situation in its entirety.

The alternative to the proposed US strike is not inaction, but rather a more comprehensive approach which takes into account the underlying reality in which the horrors at al-Ghouta took place: the proxy war in Syria. Come what may, only talks aimed at achieving a ceasefire, including wrangling with Russia and Iran, will stop the downward slide in Syria. It seems worth now unleashing that inevitable diplomatic offensive, instead of a token salvo of missiles.

Dr Alia Brahimi is a Visiting Research Fellow at the University of Oxford. She received her doctorate from the University of Oxford in 2007.