United Nations military observers left Damascus today after a four-month mission in which they became helpless spectators of Syria's spiralling conflict, instead of monitoring a ceasefire between president Bashar al-Assad's forces and rebels.
Their departure coincided with an assault by Dr Assad's forces backed by tanks and helicopters to try to retake the Damascus suburb of Mouadamiya from opposition fighters, activists said.
Twelve people, including three rebels, were killed, according to the opposition Syrian Observatory for Human Rights, a British-based group with many contacts in Syria.
Control of Mouadamiya has changed hands several times, as have many other places in a war with no clear frontlines.
"Our mission failed because the two sides did not abide by their commitments," said one uniformed observer, who declined to be named, before seven UN cars left a Damascus hotel carrying some of the last members of a mission once 300 strong.
The unarmed monitors suspended operations in June after coming under fire and most have already departed, leaving a small liaison office in the Syrian capital in case a chance for a political settlement to the bloodshed ever emerges.
US president Barack Obama bluntly warned Dr Assad this evening not to cross a "red line" by using chemical or biological weapons in his country's bloody conflict and suggested that such action would prompt the United States to consider a military response.
Pointing out that he had refrained "at this point" from ordering US military engagement in Syria, Mr Obama said that there would be "enormous consequences" if Assad failed to safeguard his weapons of mass destruction.
It was Mr Obama's strongest language to date on the issue, and he warned Syria not only against using its unconventional weapons, but against moving them in a threatening fashion.
"We have been very clear to the Assad regime, but also to other players on the ground, that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized," he said. "That would change my calculus."
"We cannot have a situation where chemical or biological weapons are falling into the hands of the wrong people," he told an impromptu White House news conference. He acknowledged he was not "absolutely confident" the stockpile was secure.
Battling a 17-month-old uprising against his family's 42-year rule, Dr Assad has used fighter jets and helicopter gunships to pound rebel strongholds. Insurgents have stepped up their attacks, hitting tanks, military convoys and security buildings.
The mandate of the monitoring mission, known as UNSMIS, expired yesterday. The last monitors are due leave by Friday.
After a brief lull, violence intensified during the monitors' presence in Syria and at least 9,000 people have been killed since they arrived to oversee a ceasefire declared on April 12th by outgoing UN-Arab League mediator Kofi Annan.
The truce never took hold. At least 18,000 people have now been killed in Syria since the anti-Assad revolt began. At least 170,000 have fled the country, according to the United Nations, and 2.5 million need aid inside Syria.
Reuters