Dear David Cameron,

As Syrians residents in the UK we have watched the rise of ISIL with greater horror than many others in the world. That is because it is our people in Syria who are on the front lines of ISIL’s brutality. It is in the central square of our beloved city Raqqa that ISIL displays the severed heads of Syrian civilians and claims its capital.

We want more than anyone to be freed of ISIL and so we welcome international commitment to rid the world of this disease. But simply bombing ISIL will not defeat them. If anything it will make them stronger.

That is because the growth of ISIL is a symptom of Assad’s indiscriminate killing of civilians. There was no ISIL in 2011 when Syrians rose up peacefully against Bashar al-Assad to demand their dignity and their rights, only to have the regime use its full military might to crush them. As the violence and destruction increased, ISIL slipped across the border from Iraq, and like a parasite established itself in the rubble of Syria's barrel bombed towns.

Not long after, many Syrians bravely drove out ISIL. From towns like Atareb and Saraqeb in the north and large parts of Idlib and Aleppo, Syrian rebel groups routed ISIL. Entire communities resisted their advances, sometimes even peacefully. But this progress was impossible to sustain while Bashar al-Assad's regime dropped banned barrel bombs on schools, hospitals and homes in areas resisting both his forces and ISIL. In the first four months of 2014, half a million people fled Aleppo as a result of the regime’s aerial campaign, many heading over the border into Turkey and on to Europe.

If we want to drive ISIL from the land that it currently holds in Syria, we need to understand that the Assad regime is a much larger threat to people on the ground. It is responsible for more than 95% of civilian deaths in Syria since the beginning of the uprising. In the first half of 2015, the regime killed seven times more civilians than ISIL. A recent survey of refugees in Europe showed that twice as many Syrians were fleeing Assad's forces than were fleeing ISIL.

In this context, selectively bombing ISIL from the air will not win the support of those on the ground who want to defeat it. It will not free them to strengthen their communities once again and resist ISIL once again.

ISIL wants nothing more than to say to the communities that it occupies that the outside world does not care about them. ISIL wants to persuade Syrians that countries like the UK are turning a blind eye to the horrors of the Assad regime and are instead choosing to attack them because this is a wider clash of civilisations. Bombing ISIL while ignoring the much greater violence of the Assad regime would feed this narrative.

The only way to defeat ISIL is by stopping the Assad regime’s indiscriminate attacks on civilian areas, including areas controlled by moderate rebel groups. Once this happens, Syrians will be freed up to drive out ISIL themselves, as they have proved themselves capable of doing.

To make this happen, the UK and other countries need to get serious about the political resolution of the conflict. The peace talks that started a few weeks ago in Vienna offer hope to build on the agreements made two years ago in Geneva for a political transition in Syria, but we need to go beyond hope. While barrel bombs continue and entire towns remain under starvation siege and hundreds of thousands of political prisoners remain in government jail, there can be no progress. There needs to be a guarantee for civilian protection from the Assad regime’s use of indiscriminate air attacks.

We are urging you Prime Minister to prioritise the resolution of the conflict in Syria over the bombing of Raqqa. It is simply not possible to defeat ISIL while Assad maintains his grip on power and keeps the war burning and refugees pouring over the borders. Once the indiscriminate attacks stop you will see how.

Kind regards,

Dr. Mohammad Tammo, Kurds House

Anna Simpson, Oxford for Syria

Dr. Mohamed Najjar, Peace and Justice in Syria

Dr. Haytham Alhamwi, Rethink Rebuild Society

Dr. Amer Masri, Scotland4Syria

Muzna Al-Naib, Syria Solidarity UK

Dr. Sharif Kaf Al-Ghazal, Syrian Association of Yorkshire

Dr. Mohammad Alhadj Ali-Syrian Welsh Society