(CNN) The stakes in Geneva couldn't be higher. At best, negotiators will help find a way to end a war that has claimed more than 270,000 lives. At worst, the bloodshed in Syria will continue unabated, with bombs falling and schools and civilians fearing that the next airstrike might kill them.
On Monday, members of both the Syrian regime and opposition are meeting in Switzerland -- albeit indirectly -- to try to find common ground. But that will be an enormous challenge.
Here's what to expect at the Syria peace talks:
The U.N.-sponsored talks will focus on a spate of tough issues, including how to govern Syria, a new constitution and presidential elections.
They're part of a "road map" for peace detailed in U.N. Security Council Resolution 2254, which the council adopted in December. That resolution calls for a political transition aimed at establishing "a credible, inclusive and nonsectarian governance" in Syria.
And the negotiations come at a fragile time for Syria -- less than a month into a shaky truce that has quelled some violence, but certainly not all.
But the regime and opposition won't face each other directly. Instead, U.N. special envoy Staffan de Mistura will speak with each side separately.
All this comes as the Syrian crisis nears its fifth anniversary Wednesday. And with 3.7 million children under the age of 5, a generation of young Syrians don't know what life without war is.
"Have they seen anything that looks like a normal life?" de Mistura asked, adding that "900 (children) were killed last year, and 150 of them while they were sitting in their own schools."
Perhaps the biggest sticking point involves the most polarizing figure in the war: Syrian President Bashar al-Assad.
Opposition leaders, the United States and their allies hold the Assad regime responsible for the mass slaughter of civilians and rebel fighters seeking an end to his family's 45-year rule.
But Assad has maintained that his regime is only fighting terrorists, and he now has the support of Russian-powered airstrikes.
Even though the U.N. Security Council resolution calls for an inclusive transitional governing body in Syria with full executive powers, asking Assad to resign would be a nonstarter, his chief envoy said Saturday.
"We will not negotiate with anyone on the presidency," Syrian Foreign Minister Walid Moallem said. "Bashar is (a) red line and belongs to the Syrian people."
A main opposition group called the High Negotiations Committee has demanded that Assad have no role in any government that would come from the peace process. That group will be at the negotiating table in Geneva.
U.S. Secretary of State John Kerry expressed dismay over Moallem's firm line about Assad, saying it was a "disruption" in the peace efforts. He called for Iran and Russia -- key backers of Assad -- to rein in the Syrian President.
"The fact is that his strongest sponsors, Iran and Russia, have both adopted at the United Nations ... an approach which dictates that there must be a political transition, and that we must move towards a presidential election at some point in time," Kerry told reporters Sunday.
"If the regime and its backers think that they can test the boundaries, diminish compliance in certain areas or act in ways that call into question their commitment to the cessation, without serious consequences for the progress that we have made, they are deeply mistaken."
The U.N. special envoy to Syria said he doesn't expect the peace talks to wrap up this week. Not even close.
"We have been aiming at three rounds. The first round is starting, God willing, today," de Mistura said Monday.
He said the second round will probably start on March 24 and will last about a week. The third round will start sometime after that.
"By then, we believe we should have a clear road map," he said. "I'm not saying we should have an agreement, but a clear road map."
Previous Syrian peace talks have produced no lasting stop to the violence. After a failed attempt in Geneva two years ago, then-U.N. mediator Lakhdar Brahimi apologized to Syrians, saying he was "very, very sorry" that "we haven't done very much."
Could this time be different?
"The very fact that we're back here again in Geneva, that both sides are here this time -- on time, it seems, for the first time ... is an indication that there is progress," said CNN International Diplomatic Editor Nic Robertson, who has reported extensively on the crisis.
"But it is glacial progress."
There are several reasons to believe this round of talks will be different, said James Gelvin, a history professor at the University of California, Los Angeles.
"First of all, Iran is involved. The United States had tried to keep Iran out of the previous talks, but since the nuclear talks, the United States is acquiescing to the fact that Iran is a player," Gelvin said.
"The second one is the fact that now you have a stalemate on the ground ... neither side is going to be able to win it on the battlefield," he said.
"And the final thing is the internationalization of the terrorism on the part of ISIS. And now the United States is very much concerned about eliminating ISIS ... and that means you have to end the Syrian civil war to do this."
De Mistura said there's no planned alternative if these talks fall through.
"As far as I know, the only Plan B available is return to war -- and to (an) even worse war than we've had so far."