Ten years after the US-led invasion of Iraq, the searing memory of what became a deeply unpopular war has made Washington policy makers reluctant to use even limited force in Syria or Iran.
"Yesterday I did not make anything to eat as there was no electricity for the entire day," says Umm Fadi, a resident of Artuz district near Damascus that has been caught up in the fighting between rebels and regime forces.
Negotiations were under way with Syrian rebels who seized 21 UN peacekeepers in the Golan Heights ceasefire zone between Syria and Israel, as rebels took total control of the key northern city of Raqa.
US Secretary of State John Kerry has promised to "empower" Syria's opposition, while warning arch-foe Iran that time for talks on Tehran's nuclear ambitions could run out.
Syria and ally Russia denounced a US pledge to provide direct non-lethal aid to rebel fighters, saying it will fuel more violence in the two-year conflict.
The United States has announced it will provide direct aid to Syrian rebels, but not the arms they had hoped for, as well as $60 million in extra assistance to the political opposition.
Syria's opposition has cancelled a planned boycott of an international conference on the two-year conflict after appeals from Britain and the US, but rejected an offer of talks from Damascus.
Turkey lashed out against Syria as the death toll from a missile strike on Aleppo rose to 58 Sunday, while a US official urged the opposition to reconsider its boycott of international meetings.
The Syrian army's use of surface-to-surface missiles on Aleppo is part of a bid to advance on the northern city, swathes of which have fallen into rebel hands since mid-2012.
Russia on Thursday accused US diplomats of blocking a UN Security Council condemnation of a bomb attack in the Syrian capital that left at least 59 dead.
A huge car bomb near the headquarters of Syria's ruling party killed nearly 60 people and caused widespread destruction in the deadliest attack to hit Damascus since the civil war erupted.
A commander of the rebel Free Syrian Army, issuing a 48-hour ultimatum, has warned his forces will target Lebanon's Hezbollah unless the militant group stops shelling territory held by the insurgents.
President Bashar al-Assad said he is confident his troops will win the conflict ravaging Syria, as new calls were made on Monday for the International Criminal Court to launch a probe into war crimes.
US Secretary of State John Kerry finally talked Sunday with Russian Foreign Minister Sergei Lavrov, who had been unavailable for days after the North Korean nuclear test.
Britain, apparently backed by a handful of European Union allies, is fighting to lift an EU arms embargo barring the supply of weapons to the Syrian rebel coalition battling President Bashar al-Assad.
Gunmen have killed an Iranian commander in Syria as rebels shot down two fighter jets and overran a town, dealing further setbacks for forces loyal to President Bashar al-Assad.
US President Barack Obama vowed to maintain the pressure on the Syrian regime and to defend human rights in the Middle East on Tuesday, but offered no new ideas to halt bloodshed in the Arab world.