Manila: Malcolm Turnbull believes "pragmatism and compromise" is the key to Syria and the terrorism it fuels, as an unstated international consensus emerges which could see a temporary reprieve for the brutal dictator President Bashar al-Assad, leaving him in place while a new power-sharing arrangement is constructed.

Assad's removal had been a non-negotiable demand for the US and its allies engaged there, with Russia unofficially backing him as it seeks to extend its sphere of influence.

A possible compromise deal with the strongman accused of the most extensive war crimes since Hitler's Nazi regime, including torture of foreigners and the slaughter of thousands of his own people including with barrel bombs, would anger many Syrians, and would be major step back by the US.

But in a slap-down to hawks including former prime minister Tony Abbott, Mr Turnbull said Syria was a "complete catastrophe" which needed a political solution and not a military invasion.

He said as a pre-requisite, the world should acknowledge the nature of Sunni grievances fuelling terrorism and recognise that stability in Syria once Islamic State is neutralised will inevitably involve power-sharing with unpalatable types including hardliners who support or even engage in terrorism.

"The approach of all the parties to a resolution in Syria has to be one undertaken in a spirit of compromise and in a spirit of pragmatism," Mr Turnbull said, speaking from the sidelines of the Asia-Pacific Cooperation Summit in the Philippines.

"Ultimately, there have been hundreds of thousands of people killed, there have been millions of people driven out of their homes, it is a complete catastrophe … what is needed is a pragmatic settlement as quickly as possible."

He said a power-sharing deal along the lines of Lebanon was possible.

The lead-up to APEC, like the G20 before it, has been overshadowed by the Paris terrorist attacks and the Syrian humanitarian disaster.

Mr Turnbull, who has now met with President Barack Obama and Russia's Vladimir Putin, has counselled in the strongest possible terms against the simplistic resort to foreign invasion.

Instead he has pushed to have those powers and Sunni Arab states drive a power-sharing bargain which could be based loosely on the Lebanon model.

Mr Turnbull's position is in lock-step with the Obama White House's stance, which is widely criticised within America. It is a comprehensive rejection of that of Mr Turnbull's predecessor, Tony Abbott who has advocated direct intervention putting Australian combat lives at risk abroad to prevent more lives being lost to terrorist attacks on Australian soil.

Describing the presence of foreign armies in that theatre at the present time as "counter-productive," Mr Turnbull said the hope of degrading and ultimately defeating Islamic State - which he mostly refers to as Daesh - remained, but any post-war settlement had to address the competing religious interests to have any hope of stability and legitimacy.

"The enmities run very deep, but plainly when you look as Daesh or ISIL, its base is a Sunni population that has felt disenfranchised, oppressed in Syria, and with very good reason, and also has felt left out of the new government in Iraq," he said.

"Plainly a political settlement that is inclusive of the various groups in Syria, were that strategy to be successful, that process of inclusion, it would of course, deprive Daesh of its support base within that country."

Mr Turnbull's call for a negotiated settlement came as French police raided an address in the Paris area of Saint-Denis in which it was reported the principle architect of the weekend's attacks and several before, Abdelhamid Abaaoud, was killed or captured.

If true, it means Abaaoud was holed up under the noses of police and less than four kilometres from the weekend's deadly attacks.

Also in Manila, Foreign Minister Julie Bishop rejected media reports that Australia had been snubbed by being left out of Vienna talks on Syria earlier this month, which have laid down an end-of-year deadline for the commencement of formal negotiations between warring parties in Syria – including potentially the Assad Ba'athist regime.

Ms Bishop described the claim as "completely unsubstantiated", noting that of 23 nations contributing militarily in Syria, 14 had not been present at the Vienna talks.

Asked if Australia's role as the second largest international contributor to the military campaign in Iraq and Syria had made Australia more of a terrorist target, especially as the US, Russia, and France step up the air campaign's intensity following the Paris attacks, Mr Turnbull said all western nations were targets.

A thwarted attack in Hannover on Tuesday evening has heightened fears of further incidents, especially in Germany which has Europe's largest Muslim immigrant population and where a terrorist attack is now officially seen as inevitable.

Lebanon's 16-year civil war eventually yielded to a complex constitutional compromise in which key offices were tied in the document to religious communities, ensuring for example that the legislature is half and half, Christian and Muslim, but that the president is a Maronite Christian, and the prime minister is a Sunni Muslim, whereas the speaker of the house, must be a Shia Muslim.

Amin Saikal, one of Australia's foremost experts in Middle-East affairs at the ANU's Centre for Arab and Islamic Studies, said it appeared the US and its allies were warming to a compromise with Assad but a deal faced major problems.

He said there were a number of other extremist groups in Syria besides IS and predicted the Russians, for example, could insist on some parties such as the Free Syrian Army not being included in subsequent elections.

"How could you have fair and free elections anyway, with so many people driven out of the country," he said.

Professor Saikal also warned that even the initial military stage of attacking IS risked enormous civilian casualties and therefore a major political "blowback" against the west, rendering a planned political stabilisation even more complex.

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