On Thursday Aug. 22, president Barack Obama faced growing calls at home and abroad for forceful action against the Syrian government, over accusations that it carried out a massive deadly chemical weapons attack.

While the White House said it was “appalled” by reports of hundreds of people gassed near Damascus on Aug. 21, it made clear that any U.S. response must await confirmation of the attack and again demanded that Syrian President Bashar al-Assad give U.N. inspectors immediate access to the sites of the alleged attacks.

The Obama administration’s cautious response underscored a reluctance by Washington to intervene in Syria, since the country’s civil war erupted in 2011.

But if allegations of a large-scale chemical attack are verified, Obama will surely face heavy pressure to act more aggressively, possibly even with military force, in response to repeated violations of U.S. “red lines.”

The consensus in Washington and allied capitals is that a concerted international response can only succeed if the United States takes the lead. But Obama has shown no appetite for intervention, mindful of opinion polls, showing most Americans opposed to a new military entanglements in the Muslim world.

Despite that, pressure was mounting, as horrific photos and videos of alleged chemical weapons victims spread across the Internet.

In Washington, the Syrian opposition’s claims of a horrific gas attack by Assad’s loyalists sparked new calls for action from Capitol Hill.

Pressing ahead on Thursday, with a two-day bus tour in the Northeast to promote his economic agenda, Obama made no mention of Syria in his first public appearance.

“The fact that we are doing this bus tour is an indication that the president has his priorities straight while he continues to monitor what is an increasingly tragic situation in Syria,” White House spokesman Josh Earnest told reporters.

Republican Senator John McCain said the “credible reports” from Syria, suggesting that Assad’s forces had escalated their use of chemical weapons “should shock our collective conscience.”

McCain, one of the most influential voices in Congress on foreign policy matters and a harsh critic of Obama’s Syria policy, said U.S. inaction would encourage other governments to use harsh measures against their own people.

“It is long past time for the United States and our friends and allies to respond to Assad’s continuing mass atrocities in Syria with decisive actions, including limited military strikes to degrade Assad’s air power and ballistic missile capabilities,” he said in a statement.

Both Democratic and Republican congressional aides expressed frustration with what they deem the Obama administration’s failure to communicate with members of the Senate and House of Representatives on the crisis in Syria, except for members of the intelligence committees.

Democratic Senator Robert Menendez, chairman of the Senate Foreign Relations Committee, said he was “shocked and deeply concerned” about the reported chemical weapons attack and the United Nations should investigate.

But he stopped short of calling for military action.

Many members of Congress have expressed deep concern about U.S. involvement in the Syrian crisis, worried that weapons sent to the rebels that are fighting to oust Assad could end up in the hands of militants who would use them against the United States and its allies.

Bodies of people activists say were killed by nerve gas in the Ghouta region are seen in the Duma neighbourhood of Damascus August 21, 2013. Syrian activists said at least 213 people, including women and children, were killed on Wednesday in a nerve gas attack by President Bashar al-Assad’s forces on rebel-held districts of the Ghouta region east of Damascus. REUTERS/Bassam Khabieh

The Chairman of the Joint Chiefs of Staff Martin Dempsey believes intervening on the side of the rebels would not help the interests of the United States.

In a letter to Congressman Eliot Engel, Dempsey wrote on Aug. 19 that the U.S. military had the capability to destroy the Syrian air force and thus shift the balance of the two-year-old war in favor of the rebels. The general, however, doubts the benefits of doing so. 

“The use of U.S. military force can change the military balance,” Dempsey said. “But it cannot resolve the underlying and historic ethnic, religious and tribal issues that are fueling this conflict.”

Engel is an advocate of increasing U.S. military presence in Syria. He proposed the use of cruise missiles and other weapons against Assad-controlled air bases in his letter to the Chairman of the Joint Chiefs of Staff, dated Aug. 5. Dempsey has on the contrary continually warned the country’s political elite against stronger military commitment in the conflict, citing the U.S. experience in Iraq and Afghanistan. 

In his letter, Dempsey points out the factionalism of the Syrian opposition, not all of which share the Western vision of the country’s future. 

“Syria today is not about choosing between two sides, but rather about choosing one among many sides,” Dempsey says. “It is my belief that the side we choose must be ready to promote their interests and ours when the balance shifts in their favor. Today, they are not.”

Dempsey described Syria’s war as “tragic and complex.” 

Russia has spoken out on the issue, saying that reports by “biased regional media” about alleged chemical weapons use near Damascus might be “a provocation planned in advance,” Russian Foreign Ministry spokesman Aleksandr Lukashevich said in statement Aug. 21.

The Russian Foreign Ministry, citing its sources, said that a homemade rocket, carrying unidentified chemical substances, had been launched from an area controlled by the opposition.

“A homemade rocket with a poisonous substance that has not been identified yet – one similar to the rocket used by terrorists on March 19 in Khan al-Assal – was fired early on August 21 from a position occupied by the insurgents,” Lukashevich said.

Russia said the incident should be thoroughly investigated by professionals. Moscow urged everyone who has influence on the rebels to do everything possible to finally put an end to “such provocations involving chemical poisonous substances.”

Syrian authorities have called allegations against their forces “illogical and fabricated,” pointing to the timing of the attack and their previous assertions that, if they possessed chemical weapons, they would never use them against Syrians.

The United States, Britain and France, three veto-wielding permanent members of the Security Council, made a strong push for an “urgent” U.N. investigation of the alleged use of chemical weapons Wednesday in Syria.

The UK Deputy Permanent Representative Ambassador Phillip Parham told reporters on Aug. 22 that a letter, signed by over 35 member states, was being delivered to Secretary-General Ban Ki-moon for a “swift investigation.”

But he refused to identify the countries, nor was the letter made public.

The letter did not contain a list of signatories. The only three permanent members taking the lead, and whose signatures appear on the letter, were the United States, Britain and France.

Both Russia and China, the other two permanent members, were not signatories.

The letter, dated Aug. 21, says: “We would like to bring to your attention credible reports of the use of chemical weapons on 21 August 2013 in Rif Damascus. Given the gravity of these reports, we judge it essential that all the pertinent facts are swiftly investigated.”

The letter requests Ban to “report back to Member States as soon as possible.”

Currently, there is a U.N. team in Damascus, trying to investigate earlier attacks with chemical weapons in rural Aleppo, but the team’s mandate is limited to whether or not chemical weapons were used last year. And the team does not have a mandate to pin the blame, either on the Syrian government, or the rebels.

“We are aware that the UN Mission is now in Damascus,” the letter notes. “We urge you to do all you can to ensure that the Mission has urgent access to all relevant sites and sources of information.”

French Foreign Minister Laurent Fabius said world powers must respond with force, if allegations that Syria’s government was responsible for the deadliest chemical attack on civilians in a quarter-century prove true. But he stressed there was no question of sending in troops on the ground.

Britain, too, said no option should be ruled out “that might save innocent lives in Syria.” And Turkey said “all red lines” had been crossed in Syria and criticized international inaction.

Israel said it believed Syrian forces had used chemical weapons in the killing of hundreds of people in the rebel-held suburbs of Damascus and it accused the world of turning a blind eye to such attacks.  

— Reuters, RT, UPI, TAAN