By Tom Miles and John Irish
GENEVA (Reuters) - When Syria peace talks restart in Geneva on Thursday after 10 months in the deep-freeze, familiar disagreements are likely to resurface, despite massive changes in the military and political context.
President Bashar al-Assad's military advances, with Russian and Iranian help, have transformed the battlefield since the last U.N. talks broke up without progress in April 2016.
The political context is similarly unrecognizable, with new leadership in Washington and the United Nations and tentative coordination between Turkey, Russia and Iran.
But while a ceasefire exists, at least nominally, across most of Syria, there has been little movement on the issues that dogged previous rounds of talks.
The conflict that began with street protests six years ago has evolved into a complex multi-sided war that has killed hundreds of thousands of people and created the world's worst refugee crisis.
The opposition will press for prisoner releases, the lifting of government sieges, and above all for a political transition leading to the end of Assad's rule.
The government side is expected to stick with its view that the entire armed opposition are terrorists. And with Assad militarily stronger than he has been for years, it has the option of pressing home its advantage on the ground if it doesn't get its way at the negotiating table.
"The opposition should understand that there are new realities on the ground in Syria and international changes – it’s not like it was in 2011," said pro-Assad Syrian parliamentarian Sharif Shehadeh.
"The circumstances, the (battlefield) has changed, the political situation has changed, so they need to go with a mindset of participation, not exclusion.”
Anas al-Abdah, head of the opposition Syrian National Coalition, said: "We are fully committed to the Geneva talks and preparedto discuss a political solution and transition. We cannot address the profound security threats... while Assad remains in power."
U.N. mediator Staffan de Mistura summed up his mood as "determined" as he prepared for Syrian delegates to arrive on Wednesday. He wants to focus on reforming the governance of Syria, introducing a new constitution, and holding elections under U.N. supervision.
"MAGNET FOR TERRORISM"
Some opposition figures, western and Arab diplomats fear that if Assad stays in power, the violence will simmer for ever. A leak of a Russian-drafted constitution suggests he could continue for several seven-year terms.
"He will be a magnet for terrorism," one Western diplomat said. "It’s obvious and logical but it’s so difficult to sell as an idea, because people are so desperate for peace. People are saying: 'Why do you support terrorism? The priority is to stop terrorism, so go with Bashar.'"
The opposition says Assad is responsible for hundreds of thousands of deaths. His government blames the rebels for the bloodshed.
Western diplomats said De Mistura was hopeful of bringing the opposing Syrian factions face to face - unlike last year, when he was forced to shuttle between them in "proximity talks" that proved to be fruitless. But it was unclear whether this would be possible.
The government delegation will be led by Syria's U.N. ambassador Bashar Ja'afari, while the main opposition delegation will be headed by Nasr al-Hariri, a 40-year old cardiologist from the southern province of Deraa, where the first major demonstrations against Assad began in 2011.
Outside powers Russia and Iran, which back Assad, and Turkey and the United States, which support his opponents, will have no direct role in the talks.
A question mark hangs over the position of U.S. President Donald Trump, whose public comments have signaled he is more concerned with fighting Islamic State than with removing Assad. He appears to have withdrawn from the U.S.-Russian co-leadership that drove Syria diplomacy in the past.
"Where are the United States? I can’t tell you, because I don’t know," de Mistura said last week. "One thing I’m missing at the moment in order to have a clear equation... is aclear U.S. strategy."
Stronger contacts between Russia, Turkey and Iran brought Syrian negotiators to talks in Kazakhstan in January and this month, and briefly stirred hope of fresh impetus. But those talks, which some diplomats said might lead to a united front against designated terrorist groups, ended in disarray.
New U.N. Secretary-General Antonio Guterres has played down expectations of a breakthrough.
"Peace is only possible when none of the parties to the conflict think they can win. I’m not sure we are yet there in Syria," he said on Saturday.
"I’m afraid that some might still think, and I think it’s a total illusion, that they might win that war, so I’m not optimistic about the short-term solution for the Syria crisis."
(Writing by Tom Miles, additional reporting by John Davison and Kinda Makieh; Editing by Mark Trevelyan)