WASHINGTON – Secretary of State John Kerry says U.S. intelligence has convincing evidence the Syrian government was responsible for a deadly chemical weapons attack on its own people, including the locations from which rockets carrying the gas were launched, the time of the launches and the targets of the attack.

“We know rockets came only from regime-controlled areas, and went only to opposition-controlled or contested neighborhoods,” he added in a news conference from the State Department Friday, while making the administration’s case for a possible military strike on Syria.

However, Kerry did not provide any actual evidence backing up those assertions.

He did say the U.S. administration has released an unclassified report on the attack.

Kerry maintained, “Its findings are as clear as they are compelling. I’m not asking you to take my word for it. Read for yourself, everyone, those listening, all of you, read for yourselves the evidence from thousands of sources, evidence that is already publicly available.”

However, the document the State Department released does not show any actual evidence to support the administration’s accusation that Syria launched a chemical attack on its own people on Aug. 21.

The report states the U.S. government has “high confidence” the Syrian government carried out the attack because of assessments “based on human, signals, and geospatial intelligence as well as a significant body of open source reporting.”

But it does not provide any of those first-hand accounts or intelligence.

Kerry invoked the case made for the Iraq War, saying, “Our intelligence community has carefully reviewed and reviewed information regarding this attack. And I will tell you it has done so more than mindful of the Iraq experience. We will not repeat that moment.”

He said that is why they have “taken unprecedented steps to declassify and make facts available to people, who can judge for themselves.”

However, when his predecessor, former Secretary of State Colin Powell, made the case for going to war with Iraq, he provided evidence such as satellite photos and transcripts of intercepted communications.

Most analysts say Powell’s information was faulty while some say Iraq sent its weapons of mass destruction to Syria before the war.

But Powell did provide evidence, whereas the document released today by the State Department provides claims of evidence.

And, just Thursday many U.S. officials began insisting the intelligence picture was “not a slam dunk.”

The Associated Press called that a “reference to then-CIA Director George Tenet’s insistence in 2002 that U.S. intelligence showing Iraq had weapons of mass destruction was a ‘slam dunk.’”

Kerry offered another justification for a strike on Syria that had little to do with evidence.

The secretary of state claimed, “the credibility and the future interests” of the U.S. are on the line, as is the need to deter other regimes that may be tempted to use chemical weapons.

“It matters because a lot of other countries whose policies challenge these international norms are watching. They are watching. They want to see whether the United States and our friends mean what we say.”

He said it is important to make sure other countries “still believe the United States when it says something.”

Kerry also spelled out what the administration believes was the motive of Syrian President Bashar Hafez al-Assad.

“We know that the regime was specifically determined to rid the Damascus suburbs of the opposition, and it was frustrated that it hadn’t succeeded in doing so,” he said. “We know that for three days before the attack the Syrian regime’s chemical weapons personnel were on the ground, in the area, making preparations.”

Kerry claimed the regime’s actions immediately before the massacre provided further evidence of its culpability.

“[W]e know that the Syrian regime elements were told to prepare for the attack by putting on gas masks and taking precautions associated with chemical weapons. We know that these were specific instructions.”

Kerry says the attack itself was horrific.

“[J]ust 90 minutes later, all hell broke loose in the social media. With our own eyes we have seen the thousands of reports from 11 separate sites in the Damascus suburbs,” he said. “All of them show and report victims with breathing difficulties, people twitching, with spasms, coughing, rapid heartbeats, foaming at the mouth, unconsciousness and death.”

Kerry said at least 1,429 Syrians were killed in this attack, including at least 426 children.

“Even the first responders – the doctors, nurses and medics who tried to save them – they became victims themselves. We saw them gasping for air, terrified that their own lives were in danger.”

Administration officials say Obama is preparing to launch a limited military strike on the Syrian regime despite questions from Congress and Britain’s decision not to participate.

Analysts expect the attack to come after U.N. investigators depart Syria Saturday.

Pentagon officials confirm the Navy has moved a fifth destroyer into the Mediterranean Sea near the Syrian region.

Those ships carry dozens of Tomahawk cruise missiles.

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