In announcing their “tactical withdrawal” from the Baba Amr neighborhood in Homs after enduring a pounding by artillery, tank and sniper fire for nearly a month, the rebel Revolutionary Brigades of Baba Amr said in statement that they were both heavily outgunned and unable to justify keeping thousands of civilians marooned under dire conditions. In a quarter where most buildings are pockmarked by shell blasts, residents lack food, medicine, water and electricity, and are cut off from the outside world.

The rebel retreat was a significant victory for President Bashar al-Assad, as his troops hurry to put down an armed insurgency before international pressure grows so great or the cohesion of the armed forces breaks down under the relentless intensity of a nearly year-old uprising. The Syrian government lacks enough elite troops to subdue all rebellious cities at once; hence its strategy has been to stall for enough time to regain control of one hot spot at a time while pushing its own proposals for limited political change.

But it remains a race against exhaustion, defections and diminished resources.

The Syrian military “is not strong enough to fight in the whole country, but it is strong enough to fight civilians and defectors with light weapons,” said Akil Hashem, a retired Syrian general who has advised the Syrian National Council, the umbrella opposition group. “They don’t have enough troops to deal with all these uprisings at the same time, so they go from one to one to one.”

With the apparent victory in Homs, the Syrian military is expected to step up its assault on Hama, farther north, and beyond that try to tame Idlib Province, where many towns and large areas of the countryside have declared themselves government-free zones.

Yet international demands for a cease-fire intensify almost daily. Even Russia and China, which have repeatedly blocked any international action on Syria, voted on Thursday for a United Nations Security Council statement demanding immediate humanitarian access. In Geneva, the United Nations Human Rights Council also called on the government to permit aid into besieged areas.

The International Committee of the Red Cross said the Syrian government granted it permission to enter Baba Amr. Despite that, opposition supporters harbored a gnawing fear about possible reprisals in Homs, with gunfire still crackling there and sketchy reports of raids and arrests emerging. Activists said that they had been planning their retreat for days, with scores of residents led to safety before the withdrawal was announced.

Whether the military can maintain momentum, and for how long, remains unknown as the rebels try to regroup. What is certain is that the Assad family has long maintained a firm grip on the military.

“For 40 years this army was structured and shaped for the worst-case scenario, which is happening today, and that is why it is holding,” said Elias Hanna, a retired Lebanese Army general and military analyst.

There is no straightforward yes-or-no answer about the military’s long-term viability; its opaque nature means that assessing even basic statistics like the number of active-duty soldiers involves some guesswork.

But from the outset of the uprising last March, the forces buttressing the rule of Mr. Assad enjoyed several distinct advantages.

First, as the rebels and residents in Baba Amr learned through wrenching experience, the government commands overwhelming firepower, including tanks, heavy artillery and, if needed, helicopter gunships or warplanes.

Second, the officer corps, the intelligence services and the most elite units — including the Republican Guard and the Fourth Division commanded by the president’s brother Maher — are staffed mainly by Alawites, the minority sect of the president. The ruling family has convinced them that they face annihilation if they fail to crush the uprising.

Third, in a police state like Syria, military officers are monitored constantly, and even in villages claimed by the opposition, informants help the secret police track events.

In comparison, the opposition deploys only light weapons, including a few mortars and rocket-propelled grenades that at best can disable tanks. It has no organized command and control structure, although the Syrian National Council announced Thursday that it was forming one. But thus far, the military opposition centered on the Free Syrian Army in Turkey struggles with personal bickering, much like the political opposition.

The insurgents are highly motivated, however, and over time, demographics should tip in their favor. Alawites constitute about 12 percent of the 23 million Syrians. Sunni Muslims, the opposition’s backbone, make up about 75 percent of the population.

It would take time for those numbers to have an effect, however, perhaps a year or more, analysts said, so any quicker change in fortunes would require a wild card.

Although both Saudi Arabia and Qatar have voiced support for arming the opposition, there is no sign that they have followed through or that bigger weapons are arriving. In Iraq, for example, when Iran and Syria armed the insurgents, there was a surge in armor-piercing explosive devices and attacks on more prominent targets.

On the government side in Syria, no cracks have emerged, analysts note, nor has the steady drumbeat of soldier burials in Alawite villages prompted significant grumbling.

Nearly a year after the uprising started, Syria is marked by the “cohesion of the elites,” James R. Clapper, the director of American intelligence, told the Senate Armed Forces Committee recently.

“Short of a coup or something like that, Assad will hang in there and continue to do as he’s done,” Mr. Clapper said. “Assad himself, probably because of his psychological need to emulate his father, sees no other option but to continue to try to crush the opposition.”

The answer about the relative strength of the government forces lies in just how many soldiers Mr. Assad can deploy. Estimates of the size of his army and intelligence services range from about 250,000 to a high of 560,000. The bulk are young recruits doing military service. Estimates of elite Alawite troops range from 60,000 to three times that, with the fatigue factor considered high from repeated deployments.

Mr. Clapper, in his Senate testimony, said that 80 percent of the government’s “maneuver units,” or its tanks and artillery, had been deployed in the past year, a high number.

Defections are a factor, but not a decisive one. A recent video posted on YouTube purported to show an entire unit of some 500 men defecting en masse. Overall numbers range from about 2,250 to 20,000.

Amin M. Hotait, another retired Lebanese general and strategic analyst, who favors the lower figure, said defectors numbered less than the percentage of soldiers who could be expected to go AWOL during any conflict.

The government also recruited tens of thousands of well-paid thugs, or “shabiha,” to suppress dissent. But while they are given free range to stamp out demonstrations, the army has had to deploy its best units to recapture Homs and other cities with organized militias.

A senior United States official estimated that the military effort cost Syria $1 billion a month. Its foreign reserves have shrunk to $10 billion or less, analysts said, although there is widespread speculation that Iran and Russia are replenishing them.

Amid the fighting, a sectarian divide has developed between the Alawites and much of the population. During the biggest demonstrations to date in Damascus, on Feb. 18, Alawite civilians emerged to help suppress a mostly Sunni demonstration.

“It is a holy war for them because they have no alternative,” said a Syrian analyst, speaking anonymously for safety reasons.

On the other side, in a predominantly Sunni village outside the northern city of Idlib, for example, two defecting soldiers were shot dead by the military, a village resident who recently left Syria said. One soldier’s family, fearing the government, refused the community burial offered by the local militia.

It was ostracized.

The family of the second soldier then held a very public funeral.

Hwaida Saad and an employee of The New York Times contributed reporting from Beirut, and J. David Goodman from New York.

This article, “Syrian Forces Overwhelm Stronghold of Rebels in Homs,” originally appeared in The New York Times.