Danielle Pletka: Earlier this year, Barack Obama announced that a red line for the United States would be Syrian President Bashar al-Assad’s movement, transfer or use of Syria’s ample chemical weapons stockpile. At the time, it appeared the president was looking for an opportunity to sound tough in response to a conflict that he had heretofore chosen to observe from afar. Any prospect for the actual use of those weapons by Assad seemed farfetched.

But as the control of Syria’s terrain has slipped from Assad’s grasp, there are reportedly indications that not only has Assad moved weapons stockpiles, he has ordered precursors for Sarin nerve gas mixed in preparation for their use. As a result, the tough talk Obama embraced earlier has disappeared, as the leader of the free world and his staff contort themselves to explain that when the President earlier warned of “moving” chemical weapons as a “red line,” what he really meant was “proliferate”, not physically move. Ah.

Why would Assad use chemical weapons at this late date given threats from Washington and Europe of intervention? Perhaps he is convinced it is the last step that could decisively win him back Syria and end the civil war that has risked the Assad family’s decades-long hold on power. No matter what, the introduction of the WMD card into the Syrian equation, and Obama’s flip-flopping on what would constitute a casus belli for the United States mean that there are few serious new options to end the fighting that has claimed more than 40,000 Syrians. Rather, it seems likely that the U.S. will continue following the French and British lead, possibly recognizing a government in exile but doing little more to assist in delivering the death blow to Assad.

Are there prospects for a diplomatic solution to the fighting in Syria?  In short, no.  Either Assad goes to one of the South American proto-dictators that seems ready to welcome him, or he dies. Either way, he’s finished. The real questions that remain in Syria are the aftermath and how much more blood it will take to get there.

New to Think Tanked? Follow Think Tanked on Twitter.

James Robbins: Having drawn a line in the sand over the Assad regime’s potential use of chemical weapons, the United States must enforce its policy. Failure to do so would encourage WMD use in Syria and send a signal to other rogue states that the Obama administration is all talk.

The U.S. must mount an active campaign to dissuade the Assad regime from using chemical weapons. This effort should include the credible threat of force should Syria cross the line. The USS Eisenhower strike group and the USS Iwo Jima Amphibious Ready Group, patrolling the waters off Syria, provide ample options to respond to a variety of contingencies. The primary issue is whether Damascus believes the United States will take action.

The Assad regime must believe that the White House is serious about responding to a WMD attack, and also understand the nature and scope of the planned response. For example it would be useful to issue a public or private communiqué to the regime that U.S. military action would target not only the front-line chemical weapons troops, but all leadership nodes in the WMD decision making chain, up to and including President Assad. The United States should also drop leaflets on known chemical weapons sites warning of potential attacks. This would communicate to the regime that we know where they are hiding their weapons, and could also be highly disruptive as gun crews and missile forces desert their posts rather than face certain retribution.

Pre-emptive strikes are another option, but are not optimal. The U.S. would have to answer for whatever contamination resulted from blowing up Syria’s chemical stockpiles. This would be much easier to explain after the Assad regime made a first strike, and had lost it last shreds  of legitimacy. After that the U.S. would have a free hand to punish the regime, and should do so vigorously.

Bruce Riedel: Syria has the Arab world’s most lethal arsenal of weapons of mass destruction, hundreds of chemical warheads, dozens of Scud missiles and bombs which can deliver them anywhere in the Levant. Stopping them from falling into terrorist hands should be our top intelligence priority.

Syrian scientists developed an effective chemical weapons program using primarily the nerve agent sarin, a substance 500 times more toxic than cyanide, in the 1980s. Syria mated the nerve agent with Scud missiles and with bombs and artillery shells. When Israel learned of the Syrian program it considered military action to destroy it but concluded the program was too disbursed to be susceptible to air attacks without an unacceptable risk that Syria would respond by firing chemicals into Tel Aviv. Securing all of the arsenal today would require a very large military intervention.

As Syria collapses further into chaos over the next few months the most immediate danger is that al-Qaeda’s Syrian wing, the al-Nusra front, will take control of a military facility with a cache of chemical weapons. They could use them against Assad’s forces, or more likely spirit them into a third country to attack an American target. Jordan foiled an al-Qaeda plot to attack our Embassy in Amman this fall with mortar fire. How well al-Qaeda could maintain and use chemicals is unknown. Chemical weapons in amateur hands can be very dangerous both to the amateur and his enemy. We don’t want to take the chance.

The key to stopping al-Qaeda or Hezbollah gaining control of a cache is good real time actionable intelligence. The CIA and Mossad have had almost two years to ramp up intelligence collection on Syria but it’s a formidable challenge. U.S. and Jordanian commandoes need to be ready to secure any loose bombs.

Christopher Preble: The heart-wrenching civil war in Syria grinds on, and some commentators are beset by the desire for the United States to do something–anything–to hasten the departure of Bashar al-Assad, and secure Syria’s chemical arsenal.

We’ve seen this movie before, in neighboring Iraq. It ended badly. The better alternative is a regional solution to a regional problem, one that calls on those governments with the most at stake to take responsibility for their own security, and their interests.

The interventionists (many of whom were also great supporters of that earlier war) fail to make a compelling case for potentially putting American lives at risk this time around. The situation in Syria is horrible, but sending in U.S. troops without a clearly defined mission, reasonable expectation of success, or the support of the American people, would be worse.

A narrowly defined mission–for example, helping to ensure that Syria’s chemical weapons don’t leak out of the country–might merit U.S. action, in concert with other nations. We could offer money and material support to Syrians willing to ship out such weapons for safe disposal. Most would accept. Credible threats against those reluctant to cooperate might help seal the deal. After all, such weapons are generally more trouble than they’re worth. Leaders of nation-states with return addresses have been deterred from using such weapons against other states that could retaliate against them, so whoever takes over after Assad should be happy to rid themselves of the hassle.

Meanwhile, any terrorist organization that got its hands on these weapons would have a hard time using them. Unsurprisingly, nearly every terrorist attacks in modern history has utilized mature technologies—conventional explosives—and primitive tactics—blowing up physical things. We would be better served focusing attention and resources on those more credible threats.

Aram Nerguizian: The U.S. is increasingly concerned about the potential use of Syria’s chemical weapons against opposition forces and civilians, their lethality should safeguards fail, and concerns about proliferation should they fall into the hands of opposition fighters that include anti-U.S. jihadi groups. However, there may still be ways to maintain current safeguards and prevent proliferation.

Despite warnings that Assad is about to use these weapons, there have been no definitive indicators pointing to aggressive steps to move or deploy chemical weapons. Their use would rob Assad of what little external support he still has in Russia and China. Furthermore, Western states and their regional allies appear to continue to have access to back-channels to communicate their fears and concerns to Damascus.

So far there are signs that the regime understands what is at stake. However, if Assad is more conscious of the current balance of power in the country, he might turn to these weapons as a game-changer. It is in this context that the role of the Syrian military matters. What the role of the military may be should Assad fall is an open question. Today – for better or for worse – the Syrian military remains crucial to maintaining increasingly uncertain safeguards on Syria’s chemical weapons program.

The U.S. and its allies may be seeking Assad’s exit from power, but the experience of de-Baa’thification in Iraq informs a reluctance to dismantle Syria’s military and security apparatus as a potential source of order in any future transition. Clear movements by the military to secure Syria’s chemical weapons in the short term could vindicate this view. Meanwhile, the U.S. and allied states can use existing back-channels to make these expectations very clear to Syrian military commanders. The alternative, should these efforts fail, could be engaging in costly and uncertain military intervention.

James Quinlivan: Indiscriminate shelling, a refugee crisis, al-Qaeda-linked fighters – all these factors are driving the international community to consider intervention in Syria. But nothing is concentrating minds more than the specter of Syria breaking out its chemical weapons.

Indeed, the chemical weapons threat has raised the stakes, and negotiators need to do everything to dissuade Assad from using them. But if the weapons are used, policymakers need to prepare not only to quickly end their use, but to think past the immediate crisis and plan for the weapons’ ultimate disposal. That could entail several concrete steps.

First, control the skies. The 1988 Iraqi chemical attack that killed thousands in the Kurdish town of Halabja used the full range of chemical weapons, from mustard gas to nerve agents tabun and sarin, delivered in aerial bombs by multiple aircraft. Stopping the aircraft is an important step in removing the largest threats.

Second, resist the urge to bomb. Decision-makers need to think toward the ultimate disposal of Syria’s chemical weapon stocks, their chemical precursors, and supporting infrastructure. American bombing in the first Iraq War destroyed some chemical weapons stocks and damaged others. The Iraqis themselves later disposed of the great bulk of stocks under UNSCOM supervision. But the American bombing made that disposal more difficult and rendered some weapons so unsafe they were simply entombed in bunkers rather than destroyed.

Third, coordinate the clean-up. NATO chemical weapons specialists from the Czech Republic are already on the ground in Jordan. That may help. But unlike the aftermath of the first Iraq War, the current crisis may leave no Syrian regime competent to dispose of chemical weapons. Intervening powers may have to clean up any mess produced by their actions, as well as dispose of the existing weapons stock.

Recognizing these realities now – both their constraints on current actions and effects on future requirements – will be imperative for a successful outcome in Syria.

What do you think the U.S. should do about Syria? Share your thoughts below.