The Syrian rebels are in dire need of the sort of support that America can provide. The United States has the capability to efficiently neutralize Syria's air defenses and impose a no-fly zone to ground Assad's attack helicopters. And as Michael Doran and Max Boot pointed out in the New York Times recently, only America can lead a multinational effort to establish safe corridors between the Turkish border and the besieged city of Aleppo. Stable rebel control of Aleppo would spell the end of Assad's regime and its appalling brutality.
So what explains President Obama's hesitancy? Perhaps the caricature of liberals is true: In Libya, where Obama deployed the Air Force against the regime of Moammar Gadhafi - whose crimes were terrible, but not as terrible as Assad's - there were only marginal national-security interests. In Syria, the national-security interests are profound.
It doesn't seem plausible that Obama is hesitating because the U.S. interest is so apparent. Yet a better explanation for his passivity is elusive.
Could Obama be avoiding a messy foreign entanglement during his reelection bid? That would make him guilty of criminal negligence. Is he the sort of man who would deny innocent, endangered people help simply because it could complicate his reelection? I truly doubt it.
Here's another possible explanation: Perhaps Obama isn't quite the brilliant foreign-policy strategist his campaign tells us he is.
Of course, he has had successes. I'm not sure you're aware of this, but Osama bin Laden is dead (killed, apparently, by Obama, with only a salad fork and a No. 2 pencil). And, despite Republican assertions to the contrary, he has done far more to stymie Iran's nuclear ambitions than George W. Bush ever did.
Yet Obama's record in the Middle East suggests that missed opportunities are becoming a specialty.
Syria is the most obvious example. Assad is a prime supporter of terrorism (as opposed to Gadhafi, who had retired from terrorism sponsorship), and his regime is Iran's only important Arab ally. The overriding concern of the Obama administration in the Middle East is defanging Iran. And nothing would isolate Iran - and its Lebanese proxy, Hezbollah - more than the removal of the Assad regime and its replacement by a government drawn from Syria's Sunni majority.
Yet all we have from Obama is passivity - a recurring theme in the administration's approach to the region. So is "aggressive hedging," a term used by the Brookings Institution's Shadi Hamid to describe Obama's strange reluctance to clearly choose sides in the Arab Spring uprisings.
"There's a widespread perception in the region that Obama is a weak, somewhat feckless president," Hamid, who runs Brookings' Doha Center, told me. "Bush may have been hated, but he was also feared, and what we've learned in the Middle East is that fear, sometimes at least, can be a good thing.
"Obama's aggressive hedging has alienated both sides of the Arab divide. Autocrats, particularly in the Gulf, think Obama naively supports Arab revolutionaries, while Arab protesters and revolutionaries seem to think the opposite."
Leaders across the Middle East don't take Obama's threats seriously. Neither Israeli Prime Minister Benjamin Netanyahu nor Arab leaders believe he'll act militarily against Iran's nuclear program in his second term.
Obama's handling of Middle East peace negotiations couldn't be characterized as passive, but it could be described as thoughtless. He publicly demanded that Netanyahu freeze settlement growth on the West Bank. When Netanyahu only partially and temporarily complied, Obama did nothing.
Obama was wrong to draw a line in the sand over settlements, which are a derivative issue. But because he made it an issue without thinking about the follow-up, he managed to freeze the peace process. From the Arab perspective, Obama didn't carry through on a stated policy.
"Israeli leaders have run roughshod over Obama, embarrassing and undercutting him," Hamid said. "They simply don't believe that Obama will do anything about it."
The Middle East is a misery for American presidents. Very few, including Obama, have managed to shape events there in ways that benefit the United States.
Jeffrey Goldberg is a Bloomberg View columnist and a national correspondent for the Atlantic.