Bodies are piling up in Syria while President Bashar al-Assad sits entrenched in his palace, but the international powers say there is no alternative to UN observers watching a non-existent ceasefire.
Two bombs that exploded near UN convoys in the first month of the UN mission highlighted how the unarmed military monitors are on one of the most perilous enterprises undertaken by the United Nations. Now UN leader Ban Ki-moon says he believes Al-Qaeda was behind recent huge attacks in Damascus.
Syria is "very, very, dangerous," said Edmond Mulet, assistant secretary general for UN peacekeeping.
"They are there unarmed and there is no ceasefire, there is no peace agreement, there is no dialogue between the parties and it's an urban warfare.
"This is something we have never seen before. We have never placed our military observers in a situation like this," he said.
The UN Supervision Mission in Syria (UNSMIS) is closing on its full strength of 300 monitors. But western countries are still predicting UNSMIS will not be renewed after its first 90 day mandate on July 20.
"There is a risk that at any moment military observers will be killed or injured," said Britain's UN envoy Mark Lyall Grant. "There have been some close shaves, so it is a situation we are keeping under close review."
Artillery attacks on towns have reduced since the mission deployed, but the death toll is still high.
"It is the same strategy with a different tactic," said one senior UN diplomat. "Instead of killing 100 they kill 60 and arrest 500." Rights groups and other sources say there has been an explosion in targeted killings. The UN says up to 10,000 people have been killed in the past 15 months.
Assad has shown willingness to start political talks. And the opposition is still too divided for negotiations, diplomats said.
No one has a Plan B to propose however to the peace plan of UN-Arab League envoy Kofi Annan.
"I know lots of questions have been asked about what happens if the plan fails," Annan said last week. "I am waiting for some suggestions as to what else we do. If there are better ideas I will be the first to jump onto it."
"There is no credible alternative," according to Germany's UN ambassador Peter Wittig.
So the international community is sticking with Annan's plan though most diplomats and observers say the a new Security Council battle over Syria is likely when the 90 day mandate ends.
Russia, Assad's main international ally, may demand an extension of UNSMIS, along with fellow permanent member China, and India, Pakistan and South Africa.
The United States, Britain and France, the three Western permanent members, are not yet sure how to call time on the mission. Even US officials who most opposed UNSMIS are not yet calling Annan's plan a failure.
Richard Gowan, a specialist at the Center on International Cooperation at New York University, has predicted that the Annan mission will be a "heroic failure".
But he said "it's important that the Western powers allow Annan to declare failure himself, or Russia will attack them for killing his mission.
"Annan may feel he cannot give up, as this might be the final act in his long career as an international official. But if he feels that his plan is now dead, he should realize that there is greater honor in declaring this than carrying on hopelessly," Gowan said.
The debate on Syria is expected to be taken up at the NATO summit in Chicago on Sunday and Monday.
"If Annan does not call off the attempt then it could put us in confrontation with him," said a senior western diplomat. "Then Russia will block sanctions and everything."
"If Annan recommends sanctions then Russia and China could go on the attack against him," added another Security Council envoy.
The Syrian opposition and some Middle East countries would like a military solution. "But for the moment no country in the West has signed up for this," said the envoy.
"We may well conclude down the line that (the plan) doesn't work and a different tack has to be taken. And that would be a very sad day and a tough day for the region," Annan said.