Last week, British Prime Minister David Cameron went before parliament to request support for the UK joining airstrikes against Islamic State in Syria. There could well be a vote within the week. This, however, is not the first time that Cameron has attempted to get parliament to back military intervention in Syria. In August 2013, when Cameron lost the parliamentary vote to initiate airstrikes in Syria, it had been with the intention of bombing Assad.

Critics of Cameron’s policy have rather disingenuously claimed that this is an indication of a shambolic and contradictory strategy; that where once Cameron wanted strikes against Assad, he now wants strikes against the people fighting Assad. But of course, it was the failure to intervene against Assad and to stop the anarchy in Syria the first time around that contributed to the conditions out of which Islamic State soon arose.

The criticism that Cameron will find harder to answer, however, will come from those wanting to know what the long-term strategy for Syria will look like. And that’s something that even Cameron’s own members of parliament are concerned about. Indeed, even as public sympathy for bombing ISIS has increased in the wake of the Paris attacks and the bombing of the Sharm el-Sheikh flight, there is a clear sense of unease about the lack of overarching strategy. And these reservations are not exactly unfounded. Even if Cameron manages to bring his country into the grand anti-ISIS coalition that French President Francois Hollande is so eager to assemble, there is no real sense that anyone would be prepared to commit the ground troops needed to defeat ISIS definitively, or to commit to stabilizing Syria post-ISIS.

The plan put forward by Cameron talks in vague terms about having a stronger moderate opposition, about the need for a political process for Syria, about backing representative government for the Syrian people, and about participating in humanitarian activities in a post-conflict Syria. But this is a list of desired outcomes, not a clear and credible outline of what the UK will do to achieve them. Even the more hawkish members of Cameron’s parliamentary party will be aware of the danger here, and already the opposition is adopting the argument that airstrikes without a wider plan could do more harm than good as a means to derail the prospect military intervention altogether.

Cameron also risks losing the debate if those arguing for intervention in Syria continue to make the case exclusively in terms of immediate domestic security concerns. The argument being made is that ISIS must be defeated because it poses a security threat to Brits at home. But already detractors are pointing to the Paris attacks and the bombing of the Russian plane from Sharm el-Sheikh to argue that it is those countries intervening against ISIS that are actually putting themselves most at risk.

This is why the argument for intervention in the Syrian civil war must be made on the grounds that it always should have been; the defense of international security, stability, and order. This may be a tough sell because of how vague of how far-reaching this sounds to the public and policy makers alike. But if the last four years of Syrian catastrophe tells us anything, it is that anarchy and power vacuums are not containable. Nor are they something that we can isolate ourselves from. The migrant crisis alone is waking Europeans up to that. So, as unpopular and seemingly abstract as talk about restoring and maintaining international order may be right now, it is the only approach that would have any hope of getting a grip on the chaos that has been engulfing the Middle East and North Africa, and that is now encroaching into Europe.

Onlookers may question what difference British strikes against ISIS would make at this stage. After all, the UK has significantly scaled back its military, and it is not as if there are targets in Syria that America and France aren’t already perfectly able to hit. Ultimately, the significance of British intervention comes down to a question basic moral duty and the fact that it is only right that Britain helps share the burden of combating the evil of Islamic State.