Journalists traveling with the U.N. monitors enjoyed greater freedom inside Syria than they have at perhaps any point since the uprising against Assad began in March 2011. At one point, the commander of a group of monitors in the northern city of Idlib deferred to journalists traveling with the monitors when deciding which areas to visit.

Perhaps more than anything, the monitors were caught in the middle of the violence, which happened more than once as they were subjected to fire from both sides, particularly from the government. That prevented the U.N. in some cases from visiting sites of mass killings for as long as two days.

The news of the restructured mission comes as fighting intensifies in Syria, with the government appearing to rely ever more heavily on airstrikes, especially around Aleppo, Syria’s largest city.

The peace plan brokered by Annan in March was heavily undermined by both sides. The Syrian government continued to keep heavy weapons and troops in many populated areas, and the rebels continued to arm and even stepped up attacks, despite agreement from both sides to implement a cease-fire in mid-April.

The Syrian Network for Human Rights, a group that has kept one of the most detailed lists of casualties in the conflict, had recorded more than 20,000 deaths through the end of July of civilians and rebel fighters.

The Syrian government stopped releasing statements on military casualties in June, a month in which it said 649 soldiers had been killed by rebel attacks. Prior to that, the government had said that more than 3,000 soldiers and members of the government’s security forces had been killed.

Annan resigned earlier this month. The U.N. announced this week that Lakhdar Brahimi, another longtime envoy, would take his place. It is unclear at the moment what shape the mission might take, though for now, the U.N. will maintain a small liaison force in Damascus.

Brahimi is an Algerian who most notably served as the U.N.’s special envoy to Iraq during the first half of 2004, a time when the U.S. governing body there, the Coalition Provisional Authority, selected an Iraqi interim government that was expected to supplant the American occupying forces. He resigned from the post in frustration after six months, calling Paul Bremer, the head of the authority, a “dictator.”

“Brahimi is a very savvy operator who can deal in Arabic with the Syrians,” Serwer said. “But it’s hard for me to picture any progress before the balance of forces changes. But I think it’s important for the U.N. to have somebody for the warring parties to go to in case they want to seek a political solution.”

The international community also worked to undermine the agreement, with Russia and Iran continuing to support the government with money and weapons, while the United States and others provided material and moral support to the opposition.

“The big risk for the United States is that the instability spreads and becomes more and more sectarian and ethnic,” Serwer said. “We have to keep our eye on that, and I think that argues for giving Brahimi more support than we gave to Annan.”