VIDEO-Syria Has Used Chemical Weapons, Israel Says -

By Channon Hodge, Pedro Rafael Rosado and Alyssa Kim

Seeking Proof on Syrian Chemical Weapons: The Times’s David E. Sanger on what the Obama administration is looking for before it moves on intelligence suggesting that President Bashar al-Assad of Syria used chemical weapons.

TEL AVIV — Israel declared Tuesday that it had found evidence that the Syrian government repeatedly used chemical weapons last month, arguing that President Bashar al-Assad was testing how the United States and others would react and that it was time for Washington to overcome its deep reluctance to intervene in the Syrian civil war.

In making the declaration — which went somewhat beyond recent suspicions expressed by Britain and France — Israeli officials argued that President Assad had repeatedly crossed what President Obama said last summer would be a “red line.” But Obama administration officials pushed back, saying they would not leap into the conflict on what they viewed as inconclusive evidence, even while working with allies on plans to secure the weapons if it appeared they were about to be used or handed to Hezbollah.

The declaration from Israel’s senior military intelligence analyst was immediately questioned in Washington. Officials said an investigation was necessary, but added that American intelligence agencies had yet to uncover convincing evidence that an attack on March 19, and smaller subsequent attacks, used sarin gas, a deadly agent that Syria is believed to hold in huge stockpiles.

“We are looking for conclusive evidence, if it exists, if there was use of chemical weapons,” Jay Carney, the White House press secretary, said when pressed on the Israeli assessment.

In a briefing in Tel Aviv, an Israeli military official was vague about the exact nature of the evidence, saying that it was drawn from an examination of photographs of victims and some “direct” findings that he would not specify.

Secretary of State John Kerry suggested there were mixed messages emerging from Israel, saying that he spoke to Prime Minister Benjamin Netanyahu on Tuesday morning and that the Israeli leader “was not in a position to confirm” the intelligence assessment. Israeli officials said they would not try to explain the apparent difference between Mr. Netanyahu’s statement and that of his top military intelligence officials.

At the same time, Daniel B. Shapiro, the American ambassador to Israel, said that contingency plans to address the use of chemical weapons in Syria were “very much part” of the discussions between Defense Secretary Chuck Hagel and his Israeli counterpart here on Monday.

The Israeli intelligence analyst, Brig. Gen. Itai Brun, told participants at a security conference in Tel Aviv that the Syrian government “has increasingly used chemical weapons.” That echoed accusations that Britain and France made in a letter last week to the secretary general of the United Nations, calling for a deeper investigation.

“The very fact that they have used chemical weapons without any appropriate reaction,” General Brun said, “is a very worrying development, because it might signal that this is legitimate.”

General Brun’s statements were the most definitive to date by an Israeli official regarding evidence of possible chemical weapons attacks on March 19 near Aleppo, Syria, and Damascus, the capital. Another military official, speaking on the condition of anonymity, said that the evidence had been presented to the Obama administration but that it had not fully accepted the analysis.

None of the assertions — by Israel, Britain or France — have included physical proof. Experts say the most definitive way to prove the use of chemical weapons is to collect soil samples promptly at the site and examine suspected victims.

A senior Defense Department official noted that “the use of chemical weapons in an environment like Syria is very difficult to confirm.” He added: “Given the stakes involved, low-confidence assessments by foreign governments cannot be the basis for U.S. action. The president has clearly stated that the use of chemical weapons would be a game changer. Thus, we must be absolutely confident of use before determining how to respond.”

That will not be easy. The Syrian government, which has accused insurgents of using chemical weapons and has requested that a United Nations forensics team investigate, has refused to allow that team to enter the country because of a dispute over the scope of its inquiry.

Mr. Kerry, at a meeting of NATO foreign ministers in Brussels, urged that members of the alliance be ready to respond if it was determined that Syria had in fact used chemical weapons.

But after his phone call with Mr. Netanyahu he told reporters, “I don’t know yet what the facts are,” adding, “I don’t think anybody knows what they are.”

Reporting was contributed by Thom Shanker from Amman, Jordan; Hwaida Saad from Beirut, Lebanon; Michael R. Gordon from Brussels; and Eric Schmitt and Peter Baker from Washington.