Geneva - When your job has been labelled “mission impossible,” failure may be the most likely outcome.

There is no doubt that the United Nations Special Envoy for Syria, Staffan de Mistura, has persevered through extraordinary challenges during four-and-half years in the role.

But as the UN peace drive has dragged on without evident success, Bashar Al Assad’s forces have steadily gained ground, pinning the opposition into their last bastion of Idlib while showing little interest in negotiating an end to the bloodshed.

De Mistura has meanwhile been criticised for doing anything necessary to keep the UN talks alive while letting them devolve into negotiations without substance.

The veteran diplomat’s defenders applaud his flexibility and creativity while facing an obstinate Al Assad regime.

For Emile Hokayem, senior Middle East fellow at the International Institute for Strategic Studies, trying to create the committee is “motion without movement” that will not help Syrian reconciliation.

“It’s a waste of jet fuel and diplomatic credibility. This is something that is obviously not relevant at all.”

De Mistura told the Security Council the government and opposition had not yet agreed on the makeup of the committee.

The actual work of revising Syria’s constitution therefore does not appear imminent, while the UN’s broader mandate of negotiating “political transition” in Damascus appears to be on the backburner.

De Mistura warned the Security Council that endless “consulting” had risks. He later told reporters that next month he might be able to discuss “what could be the beginning of the constitutional committee.”

For Hokayem, the constitutional project is an example of a chronic problem with the Geneva process, where diplomatic targets keep shifting in the absence of achievement.

Throughout, Al Assad has been able to nominally claim he is participating in UN talks while pressing a military campaign. “The UN should be reflecting first about whether this is worth the effort... and, more importantly, whether they are serving the Syrian people at all,” Hokayem said.

“We never get a sense from de Mistura that enough is enough.”

There are many reasons why. One example is a lack of agility, according to David Harland, the director of the Centre for Humanitarian Dialogue. “Prior to the mid-1990s, UN envoys were usually supported by a small personal staff,” whereas they have lately expanded into larger “special political missions,... including advisers dedicated to everything from gender equality to the demobilisation of child soldiers.”

De Mistura, who habitually references the importance of his “women’s advisory board,” has a staff of 92, his office said, listing its total budget over the past three years at approximately $50 million (Dh180.34 million).

In an email to AFP, de Mistura’s office defended the constitutional reform effort as “an important milestone itself and viable entry point for other reforms to come,” including UN-supervised elections, a key plank of the Geneva process.