It was fashionable during the early phase of the Syrian revolution to predict Bashar al-Assad's demise. But when the Syrian president defied all expectations and hung on to power at all cost, including hundreds of thousands of casualties, his detractors stopped forecasting.

With some hesitation, I shall throw my hat in the ring and ask whether we've finally entered a new phase in Syria: is it truly the beginning of the end for Assad and his decades' old regime?

And once again, perhaps the more important questions to ask and answer are what - not who - will replace Assad, and how - not if or when.

The latest defeat and retreat of Assad's forces from two key cities is a sign of more to come. The triumph of a new coalition of opposition parties in Idlib as well as the success of ISIL in Palmyra is a major blow to the regime.

More importantly, the regime's incapacity to regroup, redeploy and recuperate its loses, whether geographic, civilian or military, have further demoralised its army over recent weeks and months.

Changing momentum

That's the nature of asymmetrical warfare; the longer the stronger fights the weak, the weaker it becomes. And so after four years, the fighting has finally taken its toll on the regime's military. It's exhausted, it's dispirited and it's poorly equipped.

From a strategic perspective, Assad has lost much of his power when he failed to deter or scare people into submission in the first few months of the uprising.

And once he used force and failed to defeat his enemies, and then failed again when using terrible and illegal violence against civilians and fighters alike, it all signalled that his time was up, and the countdown had started for his demise.

If he survives at all, Assad will be a tidbit militia leader for a bit longer.

Sacrificing Assad, saving Syria

Like all dictators, Assad has relied primarily on force. And when force becomes ineffective, there's little else to rely on in the absence of national or popular legitimacy. Except perhaps for his immediate loyalists.

Like all dictators, Assad has relied primarily on force. And when force becomes ineffective, there's little else to rely on in the absence of national or popular legitimacy.

But even those loyalists in the capital Damascus or from among the Alawite sect, who've become dependent on the regime, will soon conclude that it's wiser to sacrifice Assad in order to save the capital, the community and the country, than sacrifice them all in a desperate attempt to save a dictatorship.

The same applies to Assad's regional and international supporters notably, Iran and Russia. They will conclude that only by sacrificing Assad and his immediate clique of war criminals, could they save face and salvage their regional role and influence.

US secretary of State John Kerry carried a similar message to Putin last week. He reportedly interrupted the Russian president's vacation in Sochi to push for the revival of the principles of the Geneva-1 talks on Syria in order to avoid the collapse of the state along with the regime.

These principles focus on negotiations between elements of the regime (minus Assad & co.) and the coalition of the opposition parties (minus ISIL and Jabhat al-Nusra) over power sharing and national reconciliation.

It's far from ideal, but under the circumstances, it's the only way to salvage what's left of the country.

Cynicism bordering on criminality

The US and Russia agree on the need to maintain the Syrian state structure at any cost in order to avoid total uncontrollable chaos with a spillover effect on the rest of the region.

But they disagree on when or how Assad goes. The Obama administration wants him out at the beginning of the reconciliation process, while Russia insists that he goes out at the end of the process, if at all.

Meanwhile, ISIL is growing and countless more Syrians are dying in vain.

And as usual, Russia is playing chess with the US. Before it compromises on Syria, it wants something in return on Ukraine, including lifting the sanctions. And that doesn't seem to be forthcoming unless Russia makes a similar goodwill gesture.

But there might still be some change in Russia's position because of the festering disagreement with Iran. While Moscow and Tehran have long supported Assad, Russia suspects Iran cares less about the survival of Syria than the survival of its Syrian allies.

But Iran has a strategic calculation of its own, and it's not very different from those of Russia. Tehran considers Iraq its Ukraine and could eventually sacrifice Assad for greater US concessions there.

Last week's US green light for the Iranian supported Popular Mobilisation militias to fight ISIL in Ramadi reflects this new reality. It's the type of US-Iran coordination that could pave the way for strategic bartering wherein Iran sacrifices Damascus to gain more influence in Baghdad.

After Assad

Having said all this, there's only one sane way forward for Syria: negotiations and reconciliation to end the old Assad dictatorship and the building of a new inclusive Syria.

My guess, most Syrians have come to this conclusion but they need the push to set aside their hatred and distrust and begin to talk.

The guiding humane and democratic principles for the Syrian uprising might have been obscured by the violence of sectarian and criminal militias, but they remain alive and well.

They cannot grow in time of war; they could only flourish in the shadow of peace and stability.

That's why it's high time the US and Russia put aside their differences and use their clout to bring their regional and Syrian allies to agree on the roadmap ahead.

Marwan Bishara is the senior political analyst at Al Jazeera.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.