Before that, he said at the White House on Thursday, Syrian President Bashar al-Assad government has possible use of chemical weapons, the country in a small-scale civil war, but insisted that President Barack Obama (Barack Obama) need to be clear evidence to take action.
Disclosure creates a dilemma, who, as a "red line", Assad can not be cross-use of chemical weapons, President Obama resisting U.S. military response, some hawks Washington legislators trigger call.
Assessment of change in the White House, from a few days ago, U.S. officials said, the intelligence community believes that Assad's forces against rebels chemical nerve agents sarin different confidence. However, it pointed out that "the chain of custody is not clear."
Obama has announced the deployment of chemical weapons will be a change in the rules of the game uncertain consequences, and threatened that if it happens, his government would move carefully - the lessons of the war in Iraq began more than a decade ago in mind.
Then U.S. President George W Bush administration used inaccurate information to prove that in the pursuit into a non-existent nuclear, chemical and biological weapons and the invasion of Iraq.
Most importantly, the poll showed that most Americans, weary and disillusioned war has just ended Iraq and wound up in Afghanistan, another U.S. military action in the Muslim world no appetite.
"Given the stakes involved, we have learned from our own recent experience, intelligence assessment alone is not enough - the only credible evidence of the fact, provides us with a degree of certainty that will guide our decision-making, Miguel Rodriguez, director of the White House Office of Legislative Affairs, said the letter from members of Congress.
A senior U.S. defense official told reporters: "We have seen a very bad movie before," intelligence is believed to have driven policy decisions, in the cold light of day, proved to be wrong.
Defense officials pointed out that varying degrees of confidence "to describe the assessment of potential chemical weapons in Syria is generally recommended that the conclusion of the debate in the U.S. intelligence community.
The White House said the evaluation of the possible use of chemical weapons in Syria is based on the physiological part of the sample, but U.S. officials declined to say what kind of evidence, such as soil samples from the victim's blood or hair.
Use the sarin limited size, U.S. intelligence officials pointed out that no one has seen any possible use of chemical weapons in Syria heavy casualties.
The U.S. military has resisted being dragged into the conflict in Syria, only non-lethal assistance to the rebels trying to overthrow the Assad. Washington worried that the supply of weapons to the rebels might end up in the hands of al-Qaeda-linked fighters.
U.S. intelligence assessment confirmed that the United States close to some kind of action in Syria, military or other mobile appears.
A White House official told reporters, "In terms of our response", all the options are on the table, has been criticized for not doing enough to stop the bloodshed, the United States will consult with its allies.
The official said that the U.S. military is preparing a series of "emergencies", but declined to give details. Obama's available options may include everything from air raid commando raid on the establishment of Libya "no-fly zone", either unilaterally or in cooperation with its allies.
Unexpectedly announced
Nevertheless, Washington deflection stressed that a comprehensive survey of the United Nations on the ground in Syria - Assad to stop the advance of things need to move quickly to the intent of the action of the pressure.
Syrian Deputy Foreign Minister Faisal Mekdad, in an interview with Reuters, rejected Western and Israeli claims that government forces used chemical weapons, and said it was a "big lie", Syria to stop the probe of the United Nations.
Assad has clung to the United States has repeatedly asked him to step down. Resistance of more than 70,000 people have been killed in his family for decades of authoritarian rule. Set of military stalemate, but Assad has been able to rely on support from Russia and Iran.
State Council Middle East adviser, now a researcher Ariel Ratner said, "The reality is that as a nation, we can not declare the red line, and then do nothing when they crossed Finally, what we must do," Truman national security project.
The sudden disclosure of the Obama administration caused many off guard. Just two days after the Secretary of Defense Chuck Hagel and other U.S. officials appeared to play down Israel's assessment, there had been frequent use of chemical weapons Syria.
France and Britain also concluded that there is evidence that the conflict in Syria has chemical weapons were used.
Hegel said: "The intelligence community has for some time, and came to this conclusion in the past 24 hours to make a decision, to assess the information.
The White House said it wanted to provide a "rapid response" to the April 24 queries legislators Syrian use of chemical weapons. Legislators "Obama's letter quoted the assessment of Israel, France and the United Kingdom.
Arizona Republican Senator John McCain, one of the leading advocate for the United States deeper involvement in the Syrian conflict, said the response to the request of intelligence assessment.
"Said the President of the United States, if Bashar al-Assad's use of chemical weapons, which will be a change in the rules of the game, it crossed a red line," he said. "I think this is obvious, has crossed the red line. "
The person in charge of the Senate Intelligence Committee, Democratic Senator Dianne Feinstein expressed concern, publicly acknowledged that U.S. intelligence assessments embolden may encourage Assad and his: "He did not lose."
"Syria has the ability to kill tens of thousands of its chemical weapons, the world must come together to prevent this unity of action," she said.
In Brussels, NATO concern about the possible use of chemical weapons report, "an official said.
NATO has said in the past, any use of these weapons would be totally unacceptable, a clear violation of international law, if any party to use these weapons, we hope that from the reaction of the international community, "the official said.
Patriot interceptor missiles, NATO has sent Turkey, a member of the Syrian border alliances, will help to ensure the protection of Turkey against any missile attack, the missile is carrying chemical weapons or not, "the official added.
 



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