Criticism by Prime Minister Recep Tayyip Erdogan, who considers Mr. Assad a friend, has consistently grown. Last week, Mr. Erdogan called the behavior of Maher al-Assad, Mr. Assad's brother, who is said to have commanded the forces that retook Jisr al-Shoughour, “brutish and inhuman,” deeply angering Syrian officials.

The episode may have a more lasting impact as well.

So far, the government has relied on its support within the military and, more importantly, the intelligence services; the business elite; and the country's religious minorities, namely Christians and Alawites. After recent events, Turkish and American officials say they believe that some of the business elite have begun to turn against the state.

Minorities, meanwhile, are said to be growing more fearful over a government that has promised to deliver stability but instead finds itself in a protracted crisis.

In the hinterland of Jisr al-Shoughour, a predominantly Sunni region once a stronghold of the Muslim Brotherhood and known for its opposition to the Assad family, criticism was directed as much at Alawite neighbors as at the Syrian leadership.

Hamza, a 28-year-old day laborer, who like most interviewed refused to provide his last name, said some neighbors from Ishtabraq had joined paramilitary forces there. Another accused the government of arming Alawite neighbors, a longstanding charge.

“People in Jisr know each other very well, and they know the villagers around us and we know these villagers are Alawites from Ishtabraq,” another resident there said.

Human rights activists cautioned that the anger was that — just anger.

“If there is no political will on the part of the opposition to turn this into civil war, how would the dirt of the regime be turned into mud?” said Wissam Tarif, head of Insan, a human rights group. “I don't think it will turn into civil war, I just don't see it.”

But the man who received the text message on Monday from an Alawite friend of 25 years was grimmer, in words that suggested inevitability.

“As people, we don't want anything to happen between us,” Mohammed said by phone. “But the people in this regime are forcing us to hate Alawites.”

Hwaida Saad contributed reporting.