With the Bashar Al-Assad regime badly bloodied by last week’s assassination of its top security officials and fierce fighting over the weekend in both Damascus and Aleppo, the administration of President Barack Obama is being pressed on the U.S. role in the presumed end-game.

A Syrian rebel walks amidst the rubble of a damaged house in Azaz, northern Syria. REUTERS

On one side, neo-conservatives and other hawks insist that Washington should at least help establish air-patrolled safe zones in border regions to protect fleeing civilians, if not begin providing weapons directly to the armed opposition in order to better “shape the outcome,” as the Wall Street Journal editorial writers put it Monday.

“It’s not a question of sending NATO (sic) troops to fight in Syria – Syrians have shown they don’t need foreign troops to die for them,” wrote former Deputy Defense Secretary Paul Wolfowitz, now with the American Enterprise Institute, and Freedom House board member Mark Palmer in the London Sunday Times. “(B)ut they do need better weapons and material.”

On the other side, regional experts are urging Obama to continue resisting any military intervention, including supplying arms to what all agree is a highly fragmented opposition whose sole point of unity is hatred for the regime.

The latest round of advice comes in the wake of last week’s third veto in a row by Russia and China of a U.N. Security Council resolution threatening Syrian authorities. 

Those advances included the bombing of a meeting of the regime’s “crisis-management group,” in which at least four top security officials, including the ministers of defense and interior, were killed; the assertion of Free Syrian Army (FSA) control over checkpoints along Syria’s borders with Turkey and Iraq; and major clashes for the first time in both regime strongholds Damascus and Aleppo. 

In addition, the reported redeployment of Syrian troops from the Golan Heights region to the capital may show that the regime is feeling increasingly vulnerable. Many analysts, especially those based in the U.S., believe Assad is losing his grip on the country. 

Lately, Washington has exerted considerable pressure on Iraq, Egypt, and other countries close to Syria to prevent their air space or territory from being used to re-supply the regime with weapons from Iran, according to a Journal account published Monday.

In recent weeks, Washington has become especially concerned about Syria’s large chemical weapons stockpile and the possibility that some of it could fall – or be delivered – into the hands of extremist Islamist rebel groups or Lebanon’s Hizbullah, which is aligned with the regime. Pentagon officials have reportedly been consulting with Israeli counterparts about contingency plans for seizing or destroying the weapons under certain circumstances.

In the wake of the past week’s events, The New York Times reported Sunday that the administration has abandoned efforts at the U.N. to gain Russia’s support for Assad’s departure, and now intends to intensify its support for the rebels short of supplying them with weapons or other forms of lethal assistance and step up ongoing planning with the political opposition – as divided as it is -and the Friends of Syria group for a stable post-Assad transition.

But Paul Pillar, a former top CIA Middle East analyst now at Georgetown University, warned against U.S. efforts to try to “stage-manage the emergence of a new political order and picking winners and losers in it,” noting that Washington’s last effort to do so – in Iraq – “should have taught us how dim would be the prospects for success.” 

Fighting has continued in Syria’s commercial capital, Aleppo, as a pro-regime newspaper warned of a looming “battle of all battles.” Opposition activists said government forces shelled two rebel strongholds in the city on Thursday, and bombardment was also reported in the capital, Damascus.

Rebels were mostly forced to leave Damascus according to sources from both sides. The government now controls virtually of the capital, Damascus, after rebel assaults were stopped dead in their tracks. 

Citing an Arab diplomatic source, the pro-regime paper Al-Watan said: “Aleppo will be the last battle waged by the Syrian army to crush the terrorists and after that Syria will emerge from the crisis.”

A security source told AFP that the army was preparing for an all-out assault on rebel districts.

Rebels also brought in reinforcements, and said a regime assault appeared imminent.

Meanwhile, the United States said on Thursday it appeared that forces loyal to Syrian President Bashar al-Assad were “lining up” for a massacre in Aleppo, but again ruled out military intervention. 

U.S. State Department Spokeswoman Victoria Nuland said the U.S. did not foresee intervention without a UN Security Council mandate, where Russia has blocked efforts to rally a stronger response.

Demands that Syrian President Bashar al-Assad quit power are blocking efforts to end the 16-month-old conflict, Russian Foreign Minister Sergei Lavrov warned on Thursday.

Lavrov reiterated Moscow’s claim that support for Syrian rebel groups was tantamount to backing terrorism and said they are fanning the flames of violence. 

Western states said the resolution was intended to increase pressure on Assad to end the violence sparked by a government crackdown on pro-democracy protesters, but Russia said it could be used as an excuse for foreign intervention. 

The claim raised tensions surrounding a diplomatic spat in the UN Security Council, pitting Russia and China against their permanent veto-wielding counterparts the United States, Britain and France. Washington has said it will seek ways to tackle the crisis in Syria outside the world body.

Moscow has repeatedly criticized Western nations for encouraging Assad’s foes and said they must put more pressure on rebels to stop the violence in Syria. 

Iran has pledged more support for Syria amid mounting “foreign pressure” and promised not to leave its ally “alone in difficult times.”

“Given that powers have united to damage the Syrian nation, Iran’s stance toward Syria is not changeable – it will always stand by its Syrian brothers,” Iran’s first vice president, Mohammad Reza Rahimi, said Thursday while meeting Syria’s deputy prime minister, Omar Ibrahim Ghalawanji. 

The secretary of Iran’s National Security Council, Saeed Jalili, called relations between Iran and Syria “strategic”, saying that Tehran will support Damascus “more than before…(due to) foreign pressure.”

In response, Ghalawanji expressed his gratitude to Iran, stressing that the West’s “cruel sanctions” against Syria have hit the Syrian people more than they have affected the government.

The statements come as a Syrian delegation of 15 ministers and high-ranking officials are in Tehran on a three-day visit to seek the expansion of economic cooperation.

Tehran expressed its readiness to reconstruct facilities damaged in Syria during the uprising. 

Iran and Syria have also signed cooperation agreements which include the construction of a dam along with a power plant. At the same time, Iran reiterated it will not dispatch military units or hardware. 

Turkish security forces killed at least 15 Kurdish rebels in a raid near the country’s border with Iraq, officials have said, as Turkey’s prime minister warned his country may intervene in Syria to stop Kurdish rebels setting up base in the border region.

The region is the theater of a 28-year-old conflict between Turkish forces and fighters of the Kurdistan Workers Party (PKK). Turkish Prime Minister Recep Tayyip Erdogan was quoted by the TV 24 channel on Wednesday as saying a PKK-linked Kurdish presence could give Turkey cause to intervene militarily in Syria, as it has done repeatedly in northern Iraq since the 1991 Gulf War.