A man who identified himself as Syria’s deputy oil minister threw his support behind the Syrian opposition in a video posted on YouTube on Thursday, in what appeared to be the
highest-level defection from President Bashar al-Assad’s government since the country’s uprising began a year ago.

The move came as the black-market value of Syria’s currency plunged, apparently in response to comments this week from Sen. John McCain (R-Ariz.) calling for airstrikes against Syria, signaling renewed pressure on the embattled regime as it presses ahead with its offensive to crush dissent in protest flash points across the country.

The deputy oil minister, Abdo Hussameldin, cited the regime’s “brutal” crackdown against protesters for his decision to defect, and he urged other officials to follow suit.

“I join the revolution of this dignified people,” he declared in the video, which was made in an unidentified location.

“I have been in government for 33 years. I did not want to end my career serving the crimes of this regime. I have preferred to do what is right, although I know that this regime will burn my house and persecute my family,” he said.

Ayman Abdel Nour, who served as Assad’s adviser from 1997 to 2004 before he fell out with the regime and left the country, confirmed that the man was the deputy oil minister. But Abdel Nour, who now supports the opposition, cautioned against reading too much into the departure of an official who wielded little authority in a system that concentrates power almost exclusively in the hands of the ruling Assad family.

“In Syria, no person is important apart from Bashar al-Assad,” Abdel Nour said by phone. “If the foreign minister or the prime minister left, it wouldn’t matter. Syria is hostage to Bashar al-Assad.”

The move nonetheless offered a potentially significant indicator of disaffection within the top ranks of a government that has disappointed many in the opposition with its resilience throughout the year-old uprising.

“If confirmed, this is an important moment,” said British Prime Minister David Cameron. “It would be the highest-ranking civilian defection so far and would follow a number of military defections recently.”

Abdel Nour said he knows of many government officials who are disaffected yet dare not quit because they fear for their safety and that of their families. “They are surrounded by intelligence, and they cannot move,” he said.

The announcement came in the wake of a harsh government crackdown against the former opposition stronghold of Baba Amr, in the city of Homs, in which hundreds are feared to have died. The United Nations says at least 7,500 have been killed across the country since the uprising began last March, and activists say they believe the figure is far higher.

The Local Coordination Committees, an opposition group, said 56 people were killed Thursday, including 47 in the Homs area.

Although there have been thousands of military defections in recent months, few civilian officials are known to have turned against the regime. The attorney general of Hama, Adnan Bakkour, announced his defection in a video last August but has not been heard from since. The government said he had been kidnapped; members of the opposition fear he was tracked down and silenced.

A member of parliament representing Homs, Imad Ghalioun, fled the country and announced that he was joining the opposition in January.

Even among the military,
senior-level defections are rare, although many thousands of ordinary soldiers have deserted their units and, in many instances, banded together to fight back in the name of the rebel Free Syrian Army. The highest-ranking military defector is Brig. Gen. Mostafa Ahmad al-Sheik, who fled to Turkey in January.

Economists and currency traders said the Syrian pound was trading at slightly less than 100 to the U.S. dollar on Thursday, after plunging to 103 on Wednesday, a nearly 25 percent fall from its Tuesday value and dramatically lower than its pre-uprising level of less than 50.

The fall apparently followed McCain’s call this week for U.S.-led airstrikes against the regime. But Ayham Kamel, who tracks the Syrian economy for the Eurasia Group, said the government also appeared to have given up aggressively trying to support the Syrian pound as it seeks to conserve its depleted foreign-
exchange reserves and minimize strains on its budget.

However, he added, “I don’t think they are comfortable with this sharp depreciation, as it sends a wrong signal to the business community.”

In Cairo, former U.N. secretary general Kofi Annan, who has been appointed as the United Nations’ special envoy to Syria, warned against foreign military intervention ahead of a planned visit to Damascus on Sunday.

“I hope no one is thinking very seriously of using force in this situation,” he told reporters after meeting with the head of the Arab League and Egypt’s deputy foreign minister. “I believe any further militarization will make the situation worse.”