Israeli intelligence first confirmed Assad regime behind alleged chemical attack

The initial confirmation that the regime of Syrian President Bashar Assad was responsible for a suspected chemical weapons attack Aug. 21 came from a tip from the Israeli intelligence service, western intelligence sources tell Fox News.

A special unit of the Israeli Defense Force -- an intelligence unit that goes by the number 8200, which is a military intelligence listening unit -- has been cooperating with the NSA, sources tell Fox News.

This Israeli intelligence unit helped provide the intelligence intercepts that allowed the White House last weekend to conclude that the Assad regime was behind the attack.

Initially, according to well-placed U.S. intelligence sources, there was apparent confusion over whether chemical weapons were used and who gave the orders, but the U.S. now has access to intercepted conversations.

The administration also has satellite images that suggested the Assad regime was in the process of covering up the chemical attack by shelling the area where most of the deaths from the alleged chemical attack had occurred.

“We believe that it's too late for the U.N. inspection to be credible given the mass shelling that the regime has done in the affected areas,” State Department spokesman Marie Harf told reporters. “And we're going to make our own decisions on our own timeline about our response. Obviously we will continue consultations with our international partners around the world but we are making decisions based on our own timeline."

The Obama administration has not yet released intelligence on last week’s chemical weapons attack in Syria, in part because of concerns over what could be declassified.

However, President Obama in an interview with PBS Wednesday declared unequivocally that the United States has "concluded" that the Syrian government carried out the attack.

The report is considered a key component in the administration’s public case for intervention – and a possible military strike – in Syria.

Officials originally suggested the report would be released as early as Tuesday, but now there are hints the release may not come until at least Thursday.

The intelligence community is working through concerns about which intelligence is de-classified, because it could reveal sources and methods.

The timing of the release is important, though, because the more the report is delayed, the longer it will be before the administration steps up its public case for military action -- if they choose that route.

A senior administration official told Fox News on Wednesday that once the intelligence community finishes its formal assessment of the chemical attack, a larger and classified report will be sent to Congress that will have a lot more detail. Then the administration will publicly release a smaller declassified version.

“It is important to remember that the protection of sources and methods must be taken into account when the intelligence community determines what information can be declassified and released to the public,” the senior administration official said.

“While the Congress will receive a classified version of the assessment that includes the broad range of intelligence collected, the intelligence information we are able to provide publicly will be limited in scope.”

A senior U.S. official also confirmed a report that initially appeared in the Wall Street Journal that National Security Adviser Susan Rice wanted to get the U.N. inspectors out of Syria last weekend because the U.S. already believed it had the information it needed to confirm the Syrian government’s culpability.

A White House official would not comment on internal deliberations between Rice and U.S. Ambassador to the United Nations Samantha Power.

The Wall Street Journal quoted from an email that Rice reportedly sent Sunday to Power and others within the administration.

"The investigation is. . .too late, and will actually tell us what we already know: CW was used," Ms. Rice wrote, using the abbreviation for chemical weapons. "It won't even tell us by whom, which we already know."

U.N. inspectors have permission to be in Syria until Sunday.