WASHINGTON //The Obama administration is running out of patience with Bashar al Assad, the Syrian president, even as the United States has yet to say explicitly that it wants Mr Assad to go. But recent developments at the United Nations, where a US-backed draft resolution condemning the Syrian government is circulating, as well as an increasing sharpness of its tone over the past few weeks, suggests that the US has given up on the notion that the Syrian government will pursue reforms.
"Assad is not going to lead serious reforms, and [the administration] knows it," said Andrew Tabler of the Washington Institute for Near East Policy. "They recognise that what we are looking at here in terms of the Assad regime is systemic failure, and it's just broken."
As in the case of Egypt, where the US slowly, but eventually, turned against Hosni Mubarak, the former Egyptian president, the US position on Syria has been evolving. Mr Assad was at one point seen as a reformer in Washington, and Barack Obama, the US president, took advantage of a December recess in the US Congress, traditionally hostile to Syria, to appoint the first US ambassador to Damascus since 2005.
But in his speech on the Middle East last month, Mr Obama warned Mr Assad that he could either lead a democratic transition or "get out of the way".
On Friday, Susan Rice, the US ambassador to the United Nations, said during a news conference in New York that since Mr Obama's speech, nothing had changed in Syria.
She referred to Mr Obama's speech on May 19, when the US president said Mr Assad should oversee reforms or step aside.
"In the time that has elapsed, he is clearly not leading that process," she said.
Time is not on Mr Assad's side.
"The legitimacy that is necessary for anyone to expect change to occur under this current government is, if not gone, nearly run out," a State Department official wrote in an e-mail response to a reporter's questions on Friday.
Wayne White, a former senior State Department intelligence official and now an academic with the Middle East Institute, a Washington-based think tank, said: "It's pretty clear that Assad does not plan to back down at all. In other words, yes, he does have to go, and the international community has to begin isolating Syria as completely as possible".
Mr White said the administration had to forge a broad international coalition to ramp up pressure on Syria as the first step of what would be a long-term process of weakening the Assad regime and strengthening the opposition.
Analysts agree that there were no military options, at least in the short term, and the lack of knowledge in Washington of the opposition and its aims is a concern. Moreover, while there had been a general hardening of positions in western capitals, Russia and China have yet to come on board.
Both Russia and China stayed away from a scheduled discussion at the UN of the resolution on the Syrian crackdown on Saturday and have indicated that they might wield their veto power.
Their cooperation would be crucial, Mr White suggested, to give any weight to the only option open to the international community - isolation and economic sanctions.
"It doesn't take much to put the Syrian economy under severe pressure. If you cannot bring the Russians and the Chinese aboard, not just to pass, but to abide by a serious resolution, then the strategy begins to break down," Mr White said.
Mr Tabler said the Russians or Chinese could not continue to support Syria in the face of mounting evidence of widespread human rights abuses.
With Syrian forces re-taking control over a rebellious town in a northern border region, Turkey opened its border to accept thousands of refugees. Ankara had enjoyed improved relations with Damascus over the past years, but the Turkish government has been showing signs of losing patience.
Recep Tayyip Erdogan, the Turkish prime minister, on Sunday criticised the "savagery" of the Syrian military's use of force.
"Sadly, they don't behave like humans," Mr Erdogan said, according to the Turkish newspaper, Zaman.
If a refugee problem should grow, this could force more direct international action, said Mr White, prodded by Turkey or other neighbours affected.
"One scenario that always garners international attention is a scenario which is burdening member states with vast numbers of refugees that they cannot handle."
On the ground, the Syrian military crackdown on the opposition shows no sign of abating. Mr Assad's father, Hafez al Assad, successfully crushed a rebellion against his regime in the 1980s, and his son appears to be following in his footsteps.
Mr Tabler argued, however, that the younger Assad faced a different situation now. "Essentially, the genie is way too big for the bottle."