US officials continued to press for war against Syria yesterday, dismissing United Nations investigator Carla del Ponte’s statement that Western-backed opposition forces, not the Syrian regime of President Bashar al-Assad, had used chemical weapons.

Del Ponte’s comment, based on an investigation including extensive interviews by UN officials, tore to shreds the lie with which Washington has tried to justify its drive to war—namely, that it is attacking Syria to protect the people from Assad’s use of chemical weapons. (See also: “UN says US-backed opposition, not Syrian regime, used poison gas”).

White House Press Secretary Jay Carney summarily rejected del Ponte’s report without offering a shred of evidence to refute her statement. “We are highly skeptical of any suggestions that the opposition used chemical weapons. We find it highly likely that any chemical weapon use that has taken place in Syria was done by the Assad regime. And that remains our position,” Carney stated.

There is every reason to believe, in fact, that the opposition has used chemical weapons, as it has apparently received training on such weapons from the US or allied forces. According to a CNN report in December, the US has dispatched contractors and mercenaries for the purpose of training the rebels to “secure stockpiles and handle [chemical] weapons sites and materials.”

Opposition forces have received numerous shipments of weapons and equipment overseen by the United States and allied regimes such as Qatar, Turkey and Saudi Arabia. Last December, opposition fighters posted a video on YouTube showing them testing chemical weapons and declaring their readiness to use them.

Taking their lead from Carney, US lawmakers issued calls for a full-scale attack on Syria. Senate Foreign Relations Committee Chairman Robert Menendez (Democrat of New Jersey) submitted legislation that would officially authorize the Obama administration to arm the so-called “rebels.”

“The Assad regime has crossed a red line that forces us to consider all options,” Menendez said in a written statement, treating as fact the completely unsubstantiated claim, refuted by del Ponte, that the Syrian regime has used chemical weapons against the opposition.

Over the weekend, Senator John McCain (Republican of Arizona) asserted that Obama's “red line” on chemical weapons use has been crossed and that the time had come for a “game-changing” escalation against Syria.

Senator Bob Casey (Democrat of Pennsylvania) asserted the existence of a “broad consensus” in favor of the US and its allies creating a “safe zone” inside Syria. This would involve large-scale air strikes against Syrian air defenses and the carving out of a significant portion of Syrian territory under the control of the imperialist powers.

Senator Robert Corker (Republican of Tennessee), a senior member of the Foreign Relations Committee, stated on Tuesday: “I do think we'll be arming the opposition shortly.” Corker went on to say that “we do have to change the equation… The moderate opposition groups we support are not as good at fighting.”

The senators’ calls for war come amid stepped-up military planning against Syria. On Monday, the New York Times reported that the US, Britain and France are secretly discussing coordinated air strikes for the purpose of imposing a no-fly zone over Syria. The newspaper also reported that the US military, which has been working out plans to attack Syria for months, has been told by the Obama administration to step up its planning and coordinate it with key American allies.

The braying for war from Congress and the media follows Israeli air strikes against Syria last Thursday and Sunday. There are reports that 42 Syrian soldiers were killed by Israeli strikes near Damascus.

A Hezbollah representative claimed that the Israeli attacks were launched in support of the opposition groups: “This shelling is an attempt at giving a morale boost to the terrorists and takfiris [extremists] and all those who are fighting to destroy Syria from within,” he said.

One purpose of the Israeli strikes was to test Syria's air defense capacities amid preparations for massive air strikes by the US, France and Britain. According to Anthony Cordesman of the Center for Strategic and International Studies, “Israel's success does indicate that the purely military risks in enforcing some form of no-fly or no-move zone are now more limited than when the fighting in Syria began.”

Cordesman made clear that imposing a so-called “no-fly zone” would involve large-scale war: “It would take a massive US air and cruise missile attack… difficult for even two carrier groups to carry out and sustain.”

A May 7 editorial in the Wall Street Journal, “The Non-Intervention War,” made the case for a major war against Syria. The Journal wrote, “The US could still steer this conflict toward a better outcome if Mr. Obama has the will. At this stage this would require more than arming some rebels. It probably means imposing a no-fly zone and air strikes against Assad's forces. We would also not rule out the use of American and other ground troops to secure the chemical weapons.

“The immediate goal would be to limit the proliferation of WMD, but the most important strategic goal continues to be to defeat Iran, our main adversary in the region. The risks of a jihadist victory in Damascus are real, at least in the short term, but they are containable by Turkey and Israel.”

The US is preparing for yet another imperialist war on the scale of the 2003 invasion of Iraq. Though cynically advertised to the American public as an extension of the so-called “war on terror” against Al Qaeda, the goal of such a war will be to consolidate US imperialism’s control over the entire Middle East and its vast energy resources. The US ruling elite is not concerned about defeating “the terrorists,” who are in fact its allies.

The ease with which the Obama administration dismissed reports of Al Qaeda-linked opposition forces mounting attacks with chemical weapons is particularly significant, especially as lies about Al Qaeda acquiring WMD were a major pretext for invading Iraq. This underlies the long-running and continuing alliance between US imperialism and the most reactionary Islamist forces.

Starting in the late 1970s and throughout the 1980s, during the Soviet-Afghan war, US intelligence oversaw the arming of Islamist forces, including Osama bin Laden, who went on to fight as shock troops in US-backed wars in the Balkans and the Caucasus in the 1990s. While certain elements of Al Qaeda were targeted by the US after the September 11 attacks, Washington’s political connections with these forces were maintained during the 2000s.

For its 2011 Libyan war and now in Syria, the US mobilized Al Qaeda-linked forces of the Libyan Islamic Fighting Group and, in Syria, the Al-Nusra Front.

Secretary of State John Kerry traveled to Moscow on Tuesday, attempting to gain Russian support for US regime-change efforts in Syria. Together with China, Russia has vetoed three separate UN resolutions condemning Assad for his government’s crackdown on the US-backed “rebel” groups.

“The United States believes that we share some very significant common interests with respect to Syria—stability in the region, not having extremists creating problems throughout the region and elsewhere,” Kerry declared.

The United States and Russia reportedly agreed to organize a conference on the war that both the Assad regime and the opposition would attend.

Nevertheless, Kerry received a chilly welcome from Putin, who kept him waiting for hours and reportedly fiddled with his pen distractedly while Kerry spoke. The Russian Foreign Ministry released a statement, implicitly critical of US policy, that declared: “The further escalation of armed confrontation sharply increases the risk of creating new areas of tension and the destabilization of the so-far relatively calm atmosphere on the Lebanese-Israeli border.”