After dragging 46 bodies from the streets near his hometown on the Syrian coast, Omar lost count. For four days, he said, he could not eat, remembering the burned body of a baby just a few months old; a fetus ripped from a woman’s belly; a friend lying dead, his dog still standing guard.

Omar survived what residents, antigovernment activists and human rights monitors are calling one of the darkest recent episodes in the Syrian war, a massacre in government-held Tartus Province that has inflamed sectarian divisions, revealed new depths of depravity and made the prospect of stitching the country back together appear increasingly difficult.

That mass killing this month was one in a series of recent sectarian-tinged attacks that Syrians on both sides have seized on to demonize each other. Government and rebel fighters have filmed themselves committing atrocities for the world to see.

Footage routinely shows pro-government fighters beating, killing and mutilating Sunni rebel detainees, forcing them to refer to President Bashar al-Assad as God. One rebel commander recently filmed himself cutting out an organ of a dead pro-government fighter, biting it and promising the same fate to Alawites, members of Mr. Assad’s Shiite Muslim sect.

That lurid violence has fueled pessimism about international efforts to end the fighting. As the United States and Russia work to organize peace talks next month between Mr. Assad and his opponents, the ever more extreme carnage makes reconciliation seem more remote.

Nadim Houry, the director of Human Rights Watch in Beirut, said he sensed “a complete disconnect between diplomacy and events on the ground.”

“The conflict is getting more visceral,” he said. Without concrete confidence-building measures, he said, and with more people “seeing it as an existential struggle, it’s hard to imagine what the negotiations would look like.”

Heeding calls from their rabbis, thousands of ultra-Orthodox teenaged girls and women flooded the Western Wall early Friday morning to prevent close access by a group of women who pray in garments traditionally used by men, while hundreds of black-hatted Orthodox men heckled the group from behind, whistling, catcalling and throwing water, candy and a few chairs at them.

Scores of uniformed police hands locked hands in cordons to protect the group of about 100 women from Women of the Wall, in a tense standoff that exemplified the broad battle in Israel over identity and religion in the public sphere, where holy sites and rites like marriage, divorce and conversion have for decades been controlled by the ultra-Orthodox minority, known here as Haredim.

The confrontation came after a court ruled last month that the women should be allowed to wear prayer shawls and sing out loud at the wall, challenging years of policy and practice that had required visitors to the wall to follow ultra-Orthodox custom. Recently, women in the group had been arrested as they prayed at the wall once a month, sparking outcry among Jews worldwide and prompting a government initiative to reexamine the regulations at the site.

“All this commotion because of a group of women who want to pray to God,” Lesley Sachs, director of Women of the Wall, said after the confrontation. “We hope that the government won’t succumb to any kinds of threats or bullying and they will let us continue praying. This is part of the social battle. They need to get used to us.”

Israel’s reported airstrikes in Syria — and the threat of a retaliatory strike by the Syrian government — are likely to accelerate the decision-making of the Obama administration, which was already moving toward a sharp escalation of U.S. involvement in the two-year-old crisis.

Senior officials said the deployment of U.S. troops to Syria remains unlikely, but they have indicated that a decision will come within weeks on options ranging from the supply of weapons to the Syrian rebels to the use of U.S. aircraft and missiles to ground President Bashar al-Assad’s air power by destroying planes, runways and missile sites inside Syria.

Neither Israeli nor U.S. officials confirmed an attack Sunday morning that reportedly hit a weapons shipment in Syria — including sophisticated missiles and air defense equipment — about to be transferred to Lebanon-based Hezbollah.

But President Obama, in an interview broadcast just hours later Sunday, said Israel is justified in preventing the provision of weapons to Hezbollah.

“We coordinate very closely with the Israelis, recognizing that . . . they are very close to Syria, they’re very close to Lebanon,” Obama said in the interview, recorded Saturday with the Spanish-language Telemundo, after an earlier Israeli attack reported late Friday.

Throughout the Syrian crisis, the administration has repeatedly voiced the belief that Syria is already awash in weapons and that sending more will not tip the balance in favor of the rebels.

Now, in part because of growing confidence in the rebel Free Syrian Army, “the national security team and the diplomatic team around the president” favor increased involvement, and their views are gaining momentum despite the caution expressed by Obama’s political advisers, according to a senior Western official whose government has closely coordinated its Syria policy with Washington and who spoke before the reported Israeli strikes. The official discussed sensitive diplomatic assessments on the condition of anonymity.

The Syrian government publicly condemned Israel for a powerful air assault on military targets near Damascus early Sunday, saying it “opened the door to all possibilities,” as fear spread throughout the region that the country’s civil war could expand beyond its borders.

The attack, which sent brightly lighted columns of smoke and ash high into the night sky above the Syrian capital, struck several critical military facilities in some of the country’s most tightly secured and strategic areas, killing dozens of elite troops stationed near the presidential palace, a high-ranking Syrian military official said in an interview.

Israel refused to confirm the attacks, the second in three days, and Israeli analysts said it was unlikely that Israel was seeking to intervene in the Syrian conflict. They said the attacks in all likelihood expanded and continued Israel’s campaign to prevent the Syrian government from transferring weapons to Hezbollah, the Shiite militia and political party in neighboring Lebanon that is one of Israel’s most dangerous foes.

Rebels, opposition activists and residents said the strikes hit bases of the elite Republican Guard and storehouses of long-range missiles, in addition to a military research center that American officials have called the country’s main chemical weapons facility.

An American official said a more limited strike early Friday at Damascus International Airport was also meant to destroy weapons being sent from Iran to Hezbollah.

Concerns flared about whether Hezbollah might attack Israel in retaliation, possibly drawing Lebanon into the conflict. Israel deployed two of its Iron Dome missile-defense batteries in its northern cities. Iran’s IRNA news agency said Israel could expect a “crushing” retaliation from Syria or “the resistance,” meaning Hezbollah.

Analysts said Syria, weakened by the conflict, and Hezbollah, overstretched as it commits more forces to support the Syrian government, were unlikely to act, but they cautioned that a miscalculation by either side that set off an escalation could not be ruled out. And President Bashar al-Assad could choose to mount covert attacks on Israeli targets abroad, rather than engage its military directly.

One senior Israeli official, who spoke on the condition of anonymity, said he did not think that Israel was entering a war with Syria and suggested that Syria was unlikely to respond. Mr. Assad “has his own problems,” the official noted. “He doesn’t need Israel in the mess.”

A powerful explosion ripped through Marjeh Square in the center of the Syrian capital, Damascus, on Tuesday, killing 13 people and wounding over 70, according to state television, which showed video of what it said was the aftermath.

The bombing came a day after an explosion targeted the convoy of the Syrian prime minister, Wael Nader al-Halqi, in the affluent Mezze district of Damascus. State news media said that Mr. Halqi survived the attack, which killed five people, including a bodyguard.

The latest blast came when a booby-trapped car exploded near the back door of a building that used to house the Ministry of Interior, according to the Syrian Observatory for Human Rights, an organization, based in Britain, with a network of local antigovernment activists in Syria. The group said that the death toll could rise, as some of the wounded were in critical condition, and at least five members of the security forces were killed. State television said the dead were all civilians.

In footage on state television, fire trucks and ambulances could be heard in the background as a camera panned over debris, bloodstains on the ground and dented cars with broken windows. A thick spiraling cloud of back smoke engulfed the area as passers-by spoke on their cellphones and looked around in disbelief.

It was not clear if any individual was targeted, and no group immediately claimed responsibility. The government blamed its armed opponents, while the opposition Local Coordinating Committees blamed the government, as has often happened in a war in which information is a weapon and each side seeks to demonize the other.

An array of disparate groups are seeking to topple the Syrian president, Bashar al-Assad, including the blacklisted al-Nusra Front which recently pledged allegiance to Al Qaeda and has claimed responsibility for similar attacks in the past. Other rebel groups say they reject such tactics.

… As the violent civil war in Syria enters its third year and Mr. Assad’s opponents try to inch closer to Damascus, the city has witnessed increasingly frequent explosions, including powerful bombings that have targeted government officials, others whose targets appear random and occasional rebel mortars that sail into the center. Far more devastating has been the relentless bombardment of rebel-held suburbs — and other areas around the country — by security forces using artillery and airstrikes. More than 70,000 people have died in the conflict.

Repeatedly interrupted by applause, Mr. Obama asked his audience to recognize the Palestinian right to self-determination and justice that Israelis enjoy.

“Put yourself in their shoes - look at the world through their eyes,” he said. “It is not fair that a Palestinian child cannot grow up in a state of her own, and lives with the presence of a foreign army that controls the movements of her parents, every single day. It is not just when settler violence against Palestinians goes unpunished. It is not right to prevent Palestinians from farming their lands; to restrict a student’s ability to move around the West Bank; or to displace Palestinian families from their homes.

“Neither occupation nor expulsion is the answer,” he said. “Just as Israelis built a state in their homeland, Palestinians have a right to be a free people in their own land.”

He asked the audience to consider what kind of long-term future they want for their country, invoking the words of Ariel Sharon, the former Israeli military leader and prime minister who steered the country through multiple wars with Israel’s neighbors.

“It is impossible to have a Jewish, democratic state and at the same time to control all of Eretz Israel,” Mr. Obama said, quoting Mr. Sharon. “If we insist on fulfilling the dream in its entirety, we will lose it all.”

Hours after Palestinian militants fired at least two rockets from the Hamas-controlled Gaza Strip that crashed into the Israeli border city of Sderot on Thursday, President Obama traveled to the West Bank city of Ramallah and renewed his call for a two-state solution between Israelis and Palestinians, saying that continued Israeli settlement-building did not advance the cause of peace.

But, at a news conference with President Mahmoud Abbas, the leader of the Palestinian Authority and the secularist Fatah movement that rivals Hamas, Mr. Obama did not specifically call for a halt in settlement construction and urged both sides to press for a broad agreement that would meet two objectives: to provide sovereignty and a state for Palestinians and security for Israel.

“The core issue right now is how do we get sovereignty for the Palestinian people and security for Israeli people,” he said after almost two hours of talks with Mr. Abbas.

He added: “That’s not to say settlements aren’t important. That’s to say if we solve those two problems, the settlement issue will be resolved.”

Mr. Obama traveled to Ramallah after talks on Wednesday with Prime Minister Benjamin Netanyahu of Israel on the first day of his visit.

“I’ve been clear with Prime Minister Netanyahu and other Israeli leadership,” Mr. Obama said. “We do not consider continued settlement activity to be constructive, to be appropriate, to be something that can advance the cause of peace.”

Mr. Obama said Palestinians deserved an end to occupation and to the “daily indignities that come with it,” and a “future of hope.”

In short, he said, “Palestinians deserve a state of their own.”

The Syrian government and rebels accused each other Tuesday of firing a chemical weapon near the city of Aleppo, killing at least two dozen people in an attack that, if confirmed, would mark the first use of chemical arms and a major escalation in Syria’s two-year-old conflict.

Neither claim was independently confirmed Tuesday, nor was it clear what sort of weapon had been used in the attack. The United States, which has warned President Bashar al-Assad that a chemical attack would be a “red line” that would trigger a U.S. military response, expressed deep skepticism about the reports.

Syrian Information Minister Omran al-Zoubi said rebels fired “a rocket containing poison gases” at the town of Khan al-Assal, southwest of Aleppo, from a part of the city they control. The state-run Syrian Arab News Agency (SANA) said 25 people were killed and 86 injured in the attack. Rebels, in turn, accused forces loyal to Assad of firing a Scud missile containing deadly chemicals.

The Britain-based Syrian Observatory for Human Rights said 26 people died, including 16 soldiers. But the observatory’s director, who uses the pseudonym Rami Abdulrahman, said he could only “confirm that there was a rocket attack but not that any chemicals were used.”

In Washington, White House spokesman Jay Carney said the allegations were being studied. State Department spokeswoman Victoria Nuland characterized the Syrian claim as an attempt to discredit the opposition and said the United States has no evidence that rebels have chemical weapons capabilities.