Although the Obama administration has emphasized the red line against chemical weapons use, and although the international norm against their use carries grave importance far beyond this one war, it's not clear that this revelation will necessarily trigger much of a change in U.S. policy.
Ben Rhodes, the White House deputy national security adviser, put out a statement articulating how U.S. policy would change in response to the conclusion of chemical weapons use. He added later that the U.S. would commit military support to some rebels. Although this does upgrade the current U.S. policy from just offering the rebels non-lethal assistance – which means stuff like communications gear or medical supplies but not guns – it stops short of the no-fly zone proposed by the U.S. military:
The President has said that the use of chemical weapons would change his calculus, and it has. Our decision making has already been guided by the April intelligence assessment and by the regime’s escalation of horrific violence against its citizens.
Following on the credible evidence that the regime has used chemical weapons against the Syrian people, the President has augmented the provision of non-lethal assistance to the civilian opposition, and also authorized the expansion of our assistance to the Supreme Military Council (SMC), and we will be consulting with Congress on these matters in the coming weeks.
This effort is aimed at strengthening the effectiveness of the SMC, and helping to coordinate the provision of assistance by the United States and other partners and allies. Put simply, the Assad regime should know that its actions have led us to increase the scope and scale of assistance that we provide to the opposition, including direct support to the SMC. These efforts will increase going forward.
It's difficult to imagine these changes dramatically altering the current course of the war, which has seen Assad's forces gaining with assistance from Iran and Hezbollah.
So the obvious question is whether this news will lead to any more changes. Given Obama's clear skepticism about the merits of greater U.S. involvement and his administration's concerns about the risks, it's hard to foresee him changing course for the sake of his own, self-imposed red line. As Foreign Policy's Blake Hounshell put it recently, "Even if the White House does go ahead and decide that Obama’s murky, pinkish-reddish-orange line has in fact been crossed, it doesn’t seem prepared to do much about it. The plan is to press for a United Nations investigation of the alleged chemical-weapons use, not to fire up the B-52s."
Two things are almost sure to happen: First, the U.S. will press for the United Nations Security Council to commit to some action, even if only to issue a resolution censuring Assad, and, second, Russia and China will either water it down or veto it outright.
It is possible that Obama administration might decide, despite the risks of greater involvement in Syria, that the international norm against chemical weapons is valuable enough to merit defending. That could mean a limited symbolic response – say, bombing some Syrian facilities – or perhaps even more decisive, committed military support for the rebels, although that seems unlikely under the current circumstances.
What seems especially unlikely is that the Obama administration will bow to critics who charge that Obama must intervene in Syria or he risks losing "international credibility" by not responding with sufficient force to Syria's crossing of his red line.
Expect to hear warnings on cable TV that "the mullahs are watching." That charge is not wholly without merit, but it's worth noting, as Fareed Zakaria recently did, that the Reagan administration pulled U.S. troops out of Lebanon rather than risk involvement in that country's civil war. At the time, critics charged that he was tarnishing American credibility and that "the Soviets are watching." As it turned out, Reagan's decision was largely vindicated and American credibility survived.
In any case, world leaders are sophisticated enough to see that Obama has never shown much willingness to intervene and to grasp the difference between an earnest, specific threat and a vague red line.
That doesn't mean that the Obama administration won't respond or that it shouldn't. But so far, it does not appear persuaded that the chemical weapons red line necessarily triggers the kind of action that intervention advocates have been calling for.