The United States believes the Syrian government of President Bashar al-Assad may have used a small amount of the chemical sarin against rebels, the Obama administration said in a letter sent to several senators Thursday.

In fashioning a response to “any confirmed use of chemical weapons,” the letter warned, “the United States and the international community have a number of potential responses available, and no option is off the table.”. . .

The Obama administration has repeatedly declared that it would not tolerate the use of chemical weapons in Syria. Obama has called it a “red line” and previously warned Assad not to allow a chemical attack in a civil war that has taken an estimated 70,000 lives over the past two years. (Read the complete article here.)

Writing at WorldViews, Max Fisher cautions against drawing hasty conclusions from the evidence presented in the letter:

It’s possible, however unlikely it sounds, that these individuals were exposed to sarin gas through something other than a deliberate attack by regime forces.. . .

Libyan leader Moammar Gaddafi did not fare well against the Western intervention in his own country. So, even if the risk of sparking an intervention is small, presumably Assad forces would do it only if they really, really thought they needed to. And it’s hard to imagine that using a “small amount” of chemical weapons would do the regime forces enough good to merit the risk.

The Post’s editorial board writes that Obama must take action in response, as Britain, France, and Israel have already said they believe the regime deployed chemical weapons. From the editorial:

Many analysts believe the relatively limited use of chemical weapons until now was intended to test international reaction. If there is no response, Damascus may decide that it is free to use its chemicals on a larger scale.

Mr. Assad suggested something like that this week in a meeting with a Lebanese delegation. According to a Lebanese newspaper report, he said, “The Americans have been pragmatic from the very beginning and never pursued any course to its logical conclusion. They would eventually side with the victor.”

Post opinion writer David Ignatius writes that Russia should also take action against Assad’s government:

Assad’s use of the chemical weapons. . . violates the warnings made privately to Assad by Russia. The Russian caution towards Assad about chemical weapons was noted by Vitaly Naumkin, director of the Institute of Oriental Studies at the Russian Academy of Sciences and a Russian expert on the Middle East, in response to a question at a security conference here organized by the Institute for National Security Studies, an Israeli think tank.

The crisis should convince Russian President Vladimir Putin that it’s time to abandon his support for Assad and begin to work for a political transition in Syria. Assad is apparently so desperate that he has ignored warning about the chemical weapons not just from Washington, but also from Moscow. Will Putin really allow the Syrian dictator to use weapons of mass destruction in defiance of Russia?

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