Has a 'red line' in Syria been crossed?

And so what if it has?

There are good arguments to be made for the US directly arming Syria's rebels. But claims that nerve gas has been deployed in small quantities by the government of Syrian President Bashar al-Assad aren't really among them.

The UN said yesterday morning that a minimum of 93,000 people have been killed since Syria's civil war began in March of 2011. Later in the day Ben Rhodes, Obama's deputy national security adviser for strategic communication, put out a press release saying the US intelligence community is convinced that Assad "has used chemical weapons, including the nerve agent sarin, on a small scale against the opposition multiple times in the last year."

He continued:

The intelligence community estimates that 100 to 150 people have died from detected chemical weapons attacks in Syria to date; however, casualty data is likely incomplete.  While the lethality of these attacks make up only a small portion of the catastrophic loss of life in Syria, which now stands at more than 90,000 deaths, the use of chemical weapons violates international norms and crosses clear red lines that have existed within the international community for decades. We believe that the Assad regime maintains control of these weapons.  We have no reliable, corroborated reporting to indicate that the opposition in Syria has acquired or used chemical weapons.

The body of information used to make this intelligence assessment includes reporting regarding Syrian officials planning and executing regime chemical weapons attacks; reporting that includes descriptions of the time, location, and means of attack; and descriptions of physiological symptoms that are consistent with exposure to a chemical weapons agent.  Some open source reports from social media outlets from Syrian opposition groups and other media sources are consistent with the information we have obtained regarding chemical weapons use and exposure.  The assessment is further supported by laboratory analysis of physiological samples obtained from a number of individuals, which revealed exposure to sarin.

Now, 150 - or 1,050 - people killed by chemical weapons, or any other means, is tragic. But 1,050 as a percentage of 93,000 is 1.1 percent of the death toll from the war (which has claimed many fighters for Assad and civilian supporters of his government as well as people siding with the rebellion). So if the human tragedy of the Syrian civil war wasn't sufficient cause for getting involved in the fight at this time last week, it's hard to see why it's sufficient as a result that sarin was allegedly used.

One way that it is different, of course, is that chemical weapons could possibly be used to kill large numbers of civilians in a short frame of time, as happened in the Iraqi Kurdistan village of Halabja in 1988, the last wide-scale use of chemical weapons, which claimed 5,000 lives. So the fear is that Assad has tested the waters on sarin use with very small attacks, and might consider wider deployment if there isn't an international reaction.

Perhaps. But it's also the case that of late the Syrian army has regrouped, and with the help of Lebanon's Hezbollah, has made strategic gains. With the rebels on the back foot, he has less incentive to risk using sarin or any other chemical weapons. If the US started supplying game changing weapons like anti-aircraft or anti-tank missiles that the rebels have craved, there's an argument to be made that he'd be more likely to use chemical weapons. 

After all, the view of Assad and regime stalwarts is that they're in a truly existential battle: They can win or die, or, if they're lucky, live out their days as exiles from their homeland. The sectarian cast to much of the fighting -- the Alawite minority that Assad belongs to disproportionately supports his government -- also can't be ignored. Nor can the calls for jihad by leading Sunni preachers and the framing of war by other Sunni powers like the Muslim Brotherhood that now runs Egypt as a fight against Shiites, be ignored. (Iran is overwhelmingly Shiite and supports Assad; the Alawites are a long-ago offshoot of Shia Islam).

To be sure, Obama officials are saying that they're not going to provide serious weaponry to the rebellion, and the calculation in Washington appears to be a minor escalation to warn Assad off of further sarin use, without making him feel his back is to the wall. But it's also the case that "light" support of foreign insurgents has a way of morphing into wider entanglements, as US prestige and pride kick in.

Finally, it's worth remembering that the "red line" has in fact been a bit squiggly, though it has hardened over time.

The first "red line" set by Obama in August 2012 had enough holes in it to make an Emmental cheese maker proud. "We have been very clear to the Assad regime, but also to other players on the ground, that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized," Obama said then, "That would change my calculus."

Since then, caveats like "a whole bunch" have been rarer, with chemical weapons use spoken of in generic terms, and without specific action threatened. For instance, in December of 2012 Obama's spokesman Jay Carney said that, "our promise of significant consequences" if Assad used chemical weapons were "extremely clear and stark," without explaining what those consequences would be.

Obama also took a tougher line on March 21: "I've made it clear to Bashar al-Assad and all who follow his orders: We will not tolerate the use of chemical weapons against the Syrian people, or the transfer of those weapons to terrorists."

Well, for now, "won't tolerate" is translating as, "we'll give a little more assistance to the rebellion."

Full-scale US involvement in the conflict appears to remain a way off. 

Has Obama chosen the best path this week? Only time will tell.