DAMASCUS, Syria -- Germany revived calls Wednesday for a no-fly zone in northern Syria -- an idea that once might have greatly helped the beleaguered rebels and protected civilians from bombardment but now is more complicated, dangerous and unlikely due to Russia's air campaign supporting President Bashar Assad.
The proposal came amid international efforts to coax at least a temporary truce and as the government allowed humanitarian aid to head for besieged areas around the country, part of an effort described by a Russian official as a first step toward implementation of an agreement reached among world powers in Munich last week.
U.N. envoy Staffan de Mistura has been trying to secure aid deliveries and to improve the chances of restarting peace talks before the end of February. But those efforts have been clouded by a major government offensive north of Aleppo, where various forces backed by regional and international rivals are clashing over a crucial strip of land linking Syria's largest city to the border with Turkey.
The violence in Aleppo, which has sent tens of thousands of people fleeing toward the border, led to the collapse of indirect talks between the Syrian government and its opponents earlier this month.
It appears also to have revived a longstanding proposal to establish a no-fly zone in northern Syria, which was floated repeatedly by Turkey and other Assad opponents throughout the 5-year-old war.
A no-fly zone would potentially create a safe haven for tens of thousands of displaced Syrians and help stem the flow of refugees to Europe. But Washington has long rejected the idea, fearing it would draw U.S. forces further into the civil war.
German Chancellor Angela Merkel expressed support Tuesday for the idea and repeated it Wednesday in parliament. She said it could be done by an agreement with Assad, his backers and the coalition fighting the Islamic State group -- a proposal that analysts say is now unrealistic and more an attempt to appease Turkey.
At a news conference, Merkel said such an agreement would be "a sign of good will," suggesting she was referring to a more informal deal to halt aerial attacks, and that this could help lead to the overall cessation of hostilities agreed upon in Munich.
Enforcing a no-fly zone has become considerably more difficult since Moscow began its air campaign in Syria on Sept. 30. Russia's Deputy Foreign Minister Gennady Gatilov shrugged off Merkel's proposal, saying it would require Damascus' consent and U.N. Security Council approval.
Asked by reporters about Merkel's initiative, Russian Foreign Minister Sergey Lavrov snapped: "It's not Merkel's initiative, it's Turkey's initiative."
Kristian Brakel, an expert with the German Council on Foreign Relations, said Merkel's idea could be directed at Turkey, which sees "all their stakes in the Syrian war are just floating away."
Olaf Boehnke, a political scientist with the MERICS think-tank in Berlin and former head of the Berlin office of the European Council on Foreign Relations, said the idea could even be more for a domestic audience in Germany, where Merkel has been under increasing pressure to slow the flood of asylum seekers.
"My gut feeling is there's not even a lot of conceptual thinking behind it," he said. "Maybe it's even wishful thinking, because if you look into the technical details of a no-fly zone like we've seen in Libya, it's quite complicated."
A U.S.-led bombing campaign helped oust Libyan dictator Moammar Gadhafi in 2011, but that came with a resolution from the U.N. Security Council and agreement among NATO's 28 members. Such a scenario is almost impossible to imagine in Syria. Moscow has made it clear that it won't sign off on any such mission and has exercised its veto to block all efforts at the Security Council to sanction Damascus, its closest ally in the Middle East.
Turkish President Recep Tayyip Erdogan criticized the U.S. for not backing his country's proposals, adding that a no-fly zone would have prevented Russia's air campaign in the region and saved the lives of thousands of civilians.
"Oh America! You did not say 'yes' to 'no-fly zone.' Now the Russian planes are running wild over there, and thousands and tens of thousands of victims are dying," Erdogan said. "Weren't we coalition forces? Weren't we to act together?"
His words reflected the resentment felt by Syrian rebels, who believe a no-fly zone would have robbed Assad of his biggest asset, the aerial bombardment.
Christopher Harmer, a senior naval analyst at the Washington-based Institute for the Study of War, said not enforcing a no-fly zone is the "single biggest mistake" the West has made in Syria.
"Had the West intervened early on and denied Assad the ability to bomb his own citizens, the moderate opposition would have been ascendant and the radical opposition would not have gained as much traction," he said. Five years later and with the Russian air campaign, it is "more difficult, more complicated, more expensive and less likely," he said.
The U.S., Russia and other world powers agreed Feb. 12 on a deal calling for the ceasing of hostilities within a week, the delivery of urgently needed aid to besieged areas of Syria and a return to peace talks in Geneva.
Gatilov said "the implementation of the Munich agreements on (the) Syrian settlement has started."
A working group on humanitarian access to the besieged areas has met and is to again meet Thursday to take stock on the status of access to the areas under siege., according to de Mistura's office.
Moscow expects that another working group to deal with specifics of the planned truce would start working this week, according to a Russian diplomat, speaking on condition of anonymity because the envoy was not authorized to talk to the media due to the sensitivity of the discussions. The diplomat said the Russian side is ready for that.
Hopes of a temporary cessation of hostilities -- due to start Thursday, according to the Munich agreement -- have all but faded. At least 25 people have been killed in an airstrike on a hospital supported by Doctors Without Borders in northern Syria, the group said.
The U.N.-facilitated aid operation was going ahead, a development that U.N. spokesman Stephane Dujarric said in New York was "an incredibly important first step."
"We've had a lot of conferences, we've had a lot of speeches and commitments," Dujarric said. "I think the Syrian people want to see hard evidence that these conferences serve a purpose."
After a delay, more than 100 trucks headed to the besieged areas. Convoys of food, medicine and other assistance reached the rebel-held towns of Madaya and Zabadani, northwest of the capital, while a 35-truck convoy was to deliver aid to the rebel-held suburb of Moadamiyeh southwest of Damascus.
According to the agreement, aid would simultaneously be delivered to two communities in the northern province of Idlib that are under sieged by rebels.
"Today, we reached five besieged towns in urgent need of humanitarian assistance," said Yacoub el-Hillo, the U.N.'s humanitarian co-ordinator in Syria.
The aid was expected to reach over 100,000 people, said Dujarric, spokesman for U.N. Secretary-General Ban Ki-moon.
The convoys represent the third aid delivery to the blockaded communities after two other efforts last month. The U.N. estimates that 18 Syrian communities are under siege, affecting about half a million people.
