WASHINGTON — The Obama administration believes that U.S. intelligence has established how Syrian government forces stored, assembled and launched the chemical weapons allegedly used in last week's attack outside Damascus, the Washington Post reported, citing U.S. officials.
The administration is planning to release evidence, possibly as soon as Thursday, that it will say proves that Syrian President Bashar Assad bears responsibility for what U.S. officials have called an "undeniable" chemical attack that killed hundreds on the outskirts of the Syrian capital.
The report, being compiled by the Office of the Director of National Intelligence, is one of the final steps that the administration is taking before President Barack Obama makes a decision on a U.S. military strike against Syria, which now appears all but inevitable.
"We are prepared," Defense Secretary Chuck Hagel told the BBC on Tuesday. "We have moved assets in place to be able to fulfill and comply with whatever option the president wishes to take. We are ready to go."
Assets include four cruise-missile-armed destroyers in the eastern Mediterranean.
The timing of such a military response is being dictated by the need not only to assemble incontrovertible evidence against Assad — an important prerequisite for the administration, and the country, given the recent memories of a war based on false claims of weapons of mass destruction — but also to allow consultation with Congress and international partners.
Britain, France and Turkey have indicated willingness to contribute to military action. The administration is weighing the importance of direct international participation in an effort that U.S. forces are prepared to undertake themselves.
The safety of United Nations experts who are in Syria investigating the chemical weapons allegations is also an issue, the Post reported, citing a senior administration official who spoke about internal deliberations on the condition of anonymity.
The U.N. experts, who on Monday conducted the first of what was to be four days of on-site inspections, postponed their Tuesday visit because of security concerns. Reports of the Aug. 21 attack outside Damascus derailed their plans to visit three other sites in western Syria where chemical strikes allegedly occurred earlier, and the permission granted by the government for a two-week stay expires Sunday.
One question that is unlikely to be addressed in the intelligence report is why Assad would launch such a massive chemical strike in the face of a near-certain international response. It is a question that Russia, Assad's principal international backer, has raised repeatedly in suggesting that Syrian rebels arranged the attack to implicate the government.
In a telephone call Tuesday with British Prime Minister David Cameron, Russian President Vladimir Putin said his government "did not have evidence of whether a chemical weapons attack had taken place, or who was responsible," a statement on Cameron's official website said.
The Obama administration has rejected the possibility of rebel culpability, asserting that only the government has possession of the weapons and the rockets to deliver them. But others have speculated that the lack of an international response to the earlier, much smaller alleged chemical attacks may have emboldened Assad; that government forces last week may have mistakenly mixed the chemicals to a higher concentration than intended; or that areas with a high density of civilians may have been mistakenly targeted.
As it continued to consult with other countries, the administration earned key support from the Arab League. In an emergency meeting in Cairo, the influential organization blamed Assad for last week's alleged attack and called for the perpetrators to be brought to international justice.
The 21 league members — Syria has been suspended — stopped well short of endorsing outside military action, but they urged the U.N. Security Council to agree on "deterrent" measures.
Syrian Foreign Minister Walid al-Moualem said Tuesday that charges of chemical weapons use by the government are "categorically baseless," according to the state-run Syrian Arab News Agency, and that Syria was committed to facilitating the U.N. inspection.
"We all hear the drums of war around us," Moualem said. "If they want to attack Syria, I think that using the lie of chemical weapons is fake and not accurate, and I challenge them to show evidence."
He said the idea of a Western military strike to change the balance of power in Syria, which has been embroiled in a vicious conflict for more than two years, is "delusional and not at all possible."
To avenge what they called the "massacre" in the Damascus suburbs, al-Qaida-linked Islamist extremists among the rebels said Tuesday that they would strike Assad's security branches and infrastructure, according to a statement signed by several rebel factions.
The White House began contacting leading lawmakers for briefings that congressional officials said were to inform rather than seek permission. With Congress out of session, reaction to the crisis has been relatively muted, though a small group of House members planned to deliver a letter to Obama saying that Congress could reconvene to consider a strike beforehand.
Sen. Bill Nelson, D-Fla., says he supports U.S. military action against Syria.
"There should be moral outrage over the use of chemical weapons on innocent civilians in Syria," Nelson said in a statement Tuesday morning. "At this point I believe it appropriate to take military action with NATO and our regional allies. Inaction would only lead to greater suffering and instability in the region and would further embolden Assad."
Times Washington bureau chief Alex Leary contributed to this report.