Amidst the horror of the Paris attacks of Nov. 13, there is a glimmer of hope. The events have galvanised the Syrian peace process. The day after the attacks, a group of outside powers including the United States and Russia called for a ceasefire followed by a political transition.

This initiative may come to naught because Russia and America don�t agree on what should happen to Bashar al-Assad, Syria�s president. Moscow is his ally, while Washington says he must go.

That said, peace talks are the best chance to end Syria�s civil war, crush Islamic State, which has claimed responsibility for the Paris attacks, and stop the tide of refugees that has destabilised neighbouring countries as well as the European Union. The fact that all the relevant outside powers involved in this vicious proxy war � including Saudi Arabia, Iran, France and Turkey � have signed up to a common plan with tight deadlines, including a new constitution and free elections in 18 months, is a start.

The ceasefire is supposed to apply to the Syrian government and all other groups not deemed �terrorist� by the International Syria Support Group. As such, it will not stop attacks on Islamic State or Nusra Front, al Qaeda�s Syrian affiliate.

If this initiative bears fruit, the prospects for crushing Islamic State inside Syria will be good. A new national unity government could put its energies into that task and call for help from members of the international support group as required.

Presumably, the international community would also pour in resources to rebuild the country. It certainly should. If all this happened, Syrians � four million of whom have fled the country � could return home.

Without a ceasefire, the options look unattractive.

America and France are already bombing Islamic State from the air. This has killed some fighters, destroyed infrastructure and made it harder for its units to move around in open country. Paris launched a flurry of air strikes on Raqqa, Islamic State�s capital, on Nov. 15, targeting a munitions depot and a training camp.

Aerial bombardments over the border in Iraq have also helped both its government and Kurdish militia retake territory from Islamic State. They could have a similar effect in Raqqa, to which a group of largely Kurdish militia is advancing.

However, bombing inside heavily built-up areas risks killing innocent people. If the West does this, Islamic State would secure a propaganda coup � probably boosting its ability to recruit more fighters. Just think of the terrible publicity America suffered when it bombed a Medecins Sans Frontieres hospital in Afghanistan in October.

It is, therefore, not clear that there�s much point in broadening the targets of aerial bombardments. For the same reason, it is not obvious that involving more countries, such as Britain, in the bombing would achieve much.

Meanwhile, the other main military option � putting Western boots on the ground � is probably unthinkable for European and American politicians, even after the Paris attacks, because of the risk of casualties.

Nor would another Western invasion, which would inevitably be dubbed a crusaders� army by Islamic State, be likely to result in a stable country. The invasions of Afghanistan and Iraq certainly didn�t.

This is why it�s so important that the peace process works. Whether it does depends on what agreement can be reached on Assad�s role.

Some Western advocates of realpolitik say the West should work with Assad � on the grounds that, when he was firmly in charge, there was no Islamic State and no refugee crisis. But this ignores the fact that Syria�s president is largely responsible for the civil war and hasn�t done much to fight Islamic State. Nor has Russia, Syria�s ally.

It also ignores the fact that Assad has so brutalised Syria�s Sunni Muslims, who make up a large majority of the population, that siding with him would be seen as backing Shiites in a sectarian conflict against Sunnis. Quite apart from the immorality of such action, it probably wouldn�t be effective, because Sunnis would keep rising up against their oppressors regardless of what happened to Islamic State.

Still, it is not necessary for the West to dictate the manner or timing of Assad�s departure. This is something that the talks between the Syrian regime and the groups not deemed �terrorist� should determine.

Much will depend on how Russia now plays things. Its military intervention has taken some of the heat off Assad but not turned the conflict decisively in his favour. Russia has also signalled that it isn�t totally wedded to Assad. What�s more, it may itself have become a victim of Islamic State, which claimed responsibility for blowing up a Russia passenger jet last month in Egypt.

It�s unclear why Russia is more willing to work with the West over Syria, as its willingness to sign up to the new peace plan suggests. But it may be that it realises that it cannot solve the Syrian crisis on its own. If so, the peace process has a chance.

This article was written by Hugo Dixon for Reuters on Nov. 16, 2015. Hugo Dixon is a columnist and entrepreneur. His most recent book is "The In/Out Question: Why Britain Should Stay in the EU and Fight to Make it Better." He founded Breakingviews in 1999, and was editor and chairman until it was acquired by Thomson Reuters in 2009.