From there, he says, "it is easy to conceive how the initial limited intervention for humanitarian purposes ... turns into a joint campaign plan to assure that Assad is toppled."

Stephen Walt took to the New York Times to caution, "Airstrikes cannot eliminate Assad's chemical arsenal and are unlikely to tip the balance in favor of the rebels. And even if they did, this situation would give Assad a bigger incentive to use these weapons more widely. Assad's fall would create a failed state and unleash a bitter struggle among the various rebel factions. The Syrian uprising may have started as a peaceful reform effort, but today the most powerful rebel groups are jihadi extremists, the last people we want in power in Damascus."

The Wall Street Journal has aired the concerns of western diplomats who say that an American attack on Syria could harm efforts to halt Iran's nuclear program through negotiations. And Elizabeth O'Bagy, a senior research analyst at the Institute for the Study of War, relayed related concerns to journalist Joshua Foust:

"Iran has a significant role in the regime's decision-making process," [she] told me this week. She also pointed out multiple reports that suggest Iranian troops -- including the elite Iranian Revolutionary Guard Corps -- are guarding at least some of Assad's chemical stockpiles. Striking at those stockpiles would risk killing Iranian troops, which then would dramatically increase the chances of an accidental war with Iran. Is that really worth the risk?

Foust goes on to argue that "though not as strong as they were two years ago, Syria still has a formidable air defense system, all of it arrayed at the coast from where U.S. Navy ships would be launching cruise missiles. To defeat that system would require a massive shock-and-awe campaign, which might not even get all of the necessary facilities on the first wave -- and which would increase the chances of still more chemical weapons use by a regime desperate to hold onto power."

Chuck Spinney persuasively argues that Americans should be alarmed by Obama Administration officials invoking Kosovo as a precedent for strikes on Syria.

His argument is bolstered by American diplomat Christopher R. Hill, a special envoy to Kosovo, who told the Washington Post, "The problem is that people expect when U.S. military assets are deployed that we will do so until the regime goes away." The newspaper says that he "he understands and supports the White House's desire to launch a strike," but with a major caveat: "The problem with Syria is that it's bombing in the absence of a political plan," he said, cautioning that the Syrian regime could respond with more chemical attacks. "Every time you drop bombs on something," he said "you can't entirely predict the results."

Ed Husain, a New York-based senior fellow for Middle Eastern studies at the Council on Foreign Relations, took to CNN Wednesday to argue against intervention:

There is no absolute certainty as to whether al Assad used chemical weapons, or rebel factions did. Al Assad has no credible motivation to use these weapons at this stage, and in this phase of the conflict. He is not losing. If, as the Russians claim, it was al Qaeda-affiliated al-Nusrah group or Free Syrian Army elements that used weapons to bait America into the conflict, then U.S. firepower would be futile in establishing how a ragtag army and terrorists obtained chemical weapons. No amount of surgical strikes on government facilities will prevent non-state actors from further use of these weapons. But if we believe that al Assad used these weapons, and launch punitive attacks on Syria, what exactly are we targeting? The secretive and globally isolated nature of the Assad regime and therefore his chemical stockpiles means that we do not know where these are located. We intervened in Libya with greater confidence because Gadhafi's chemical weapons were mostly eliminated by an international inspection arrangement prior to the Arab uprisings. By bombing Syria now we increase the risk of al Assad using chemical weapons on populations and cities that are not under government control, or to quell new rebellions. Damaging his air force and known military installation would force him to consider his more extreme options for regime survival. Syria is now a fight to the death for both sides. U.S.-led military strikes in Syria will not change the tide of the war. That is not the mission, nor is it achievable by aerial blitzing. The Syrian opposition is not a government in waiting. It is too fragmented ideologically, overwrought by al Qaeda affiliates, deeply anti-American, and dominated by suburban fighters with little control of major cities, mercenaries who are not committed to peaceful coexistence with Syria's religious Christians, nor its Jewish neighbor. Syria after al Assad will be worse. A new civil war will break out between opposition factions. By bombing Syria today, we bear the burden of the instability we leave in our wake.

And Fareed Zakaria explained his opposition to U.S. intervention in this persuasive video:

Anti-War Activists Plan Protest at White House

Late Wednesday, Code Pink's Facebook page stated, "We will be joining the Answer Coalition tomorrow in front of the White House at 6:30 PM to say NO to War in Syria! Rumor has it that we will bomb as soon as tomorrow -- let's take action NOW!" And Syrian Americans in Chicago were divided on the best course, and planned to gather for a small anti-war rally in the Loop, the city's downtown area.