BEIRUT, Lebanon — A Syrian pastry chef turned antigovernment activist, Bebars al-Talawy, has spent nearly three years in besieged rebel enclaves, growing ever more gaunt, exasperated and sick of the one red jacket he has worn month after month.

Yet when rebels and security forces struck a truce recently that could end the blockade trapping him in the last rebel-held district in the city of Homs, he did not feel safer or freer. Instead, he was sure it meant choosing surrender or death, calling it the start of “the final countdown to the end of my life.”

His predicament, and his disillusionment with all parties to the conflict, demonstrated the challenges of selling any peace deal in Syria, even as international officials praised the Homs truce as a step toward a nationwide agreement. Russia, the United States and Middle Eastern powers are pushing with new urgency for a political solution to the nearly five-year civil war as the Islamic State, incubated in the chaos of the multisided Syrian war, expands its reach, and hundreds of thousands of Syrian refugees overwhelm Europe.

But as Mr. Talawy, 25, has said in online interviews over several years, there are deep divisions in Syria over how and whether to stop the fighting — even among the tired and hungry, even within the more moderate factions that struck the deal in the Waer district of Homs, led by local men, not foreign extremists.