Syrian army's soldiers walk in a street left in ruins...

Syrian army's soldiers walk in a street left in ruins in the city of Qusayr in Syria's central Homs province, after the Syrian government forces seized total control of the city and the surrounding region. (June 5, 2013) Credit: Getty Images

Speaking from a refugee camp in Turkey last year, Middle East scholar Fouad Ajami told CNN that, like Bill Clinton, who felt ashamed for not intervening to stop the Rwandan genocide, Barack Obama will look back with regret at his refusal to use American power in Syria.

By any standard, Syria is a disaster.

But it's not Rwanda, where 800,000 Tutsis were massacred within a period of eight months. Nor is it Obama's disaster in the sense that he's responsible for what has transpired there by not intervening.

Obama has avoided intervention not because he's insensitive, incompetent, or even uninterested. He has done so because his options aren't just bad, they're terrible. Syria is already a disaster, but a ham-handed intervention could make matters worse, certainly for America.

The commentariat is looking for ways to press the administration to act. Their arguments are largely correct: Syria is indeed a moral, humanitarian, and strategic disaster. But their prescription for action is long on generalities and short on specifics, and even fuzzier on how the United States could stabilize the country and then extract itself from yet another entanglement in the Middle East. No analogy is all that relevant here - not Rwanda, not Libya, not Bosnia. The Syrian calamity is unique.

The American experience in Afghanistan and Iraq looms large over the Syrian conflict. The parallel that's worth paying attention to isn't boots on the ground - it's the question of connecting means to ends. In the Syrian case, the central question is: How does militarizing the American role - through providing arms to the rebels, creating a no-fly zone, or even launching military strikes - pave the way for a successful outcome?

None of the incremental steps that have been proposed so far have answered the following questions: Can these actions degrade Syria's military power so that President Bashar Assad's regime collapses? Or, alternatively, can they produce a stalemate that would force the regime, the Russians, and Iran to accept a negotiated transition? Even if Assad falls, why do we believe that the battle in Syria will end? In the wake of the regime's collapse, the Syrian war may well expand - Alawite militias will continue the fight, opposition groups will struggle among themselves for control, and foreign powers will continue to meddle in the hopes of emerging on top of the new Syrian political order. If America wants to play in this war, so be it - but experience suggests it's the kind of arena in which we can't win.

It's not that America can't intervene militarily in Syria, or even that the options on the table are too risky. The problem is that the incremental steps being considered probably won't work without a much more sustained and aggressive military intervention. And after America's baby steps into the Syrian war don't resolve it, Obama will face a choice: He can either stand down and reveal we don't have the will to stand up, or he can escalate. On this front, I agree with my former colleague Ambassador Ryan Crocker, who argued that being heartless is better than being mindless.

Those are all good reasons to avoid intervening in Syria - but I doubt they will carry the day. By the end of the summer, more than 100,000 Syrians are likely to have died in a calamitous civil war that shows no signs of abating. As a result, the pressure to intervene will mount on the risk-averse Obama administration.

Here's why we are headed for a militarization of the U.S. role in Syria.

1. Time's starting to run out

The Syrian crisis might go on, in one form or another, for years. But the Obama presidency won't. The president's awareness that the clock's ticking - and that there's no third term on the horizon - will increasingly weigh on his decision-making.

Yes, we're only six months into Obama's new term. But second-term presidents - not to mention their advisers - quickly start to focus on what's important and what's not, because they know time is now limited. How a president will be remembered becomes critically important.

History - an important commodity for presidents - is likely to judge Obama very unkindly for his passivity. From where we sit today, it is easier to reach the conclusion that Syria is a trap for America. But once Obama's term concludes, there will be a different evaluation. People will forget the details and circumstances - they will only see the dead and the wounded, the refugees and the physical devastation. They will want to know why America wouldn't or couldn't do more. And that's partly why the pressure to do something will grow. Obama knows that Syria is the key story line in the so-called Arab Spring and that his own legacy will suffer unless he moves to counteract the negative appraisals currently gathering force. So, does he want to share the legacy of the last Democratic president, who failed to intervene in Rwanda and almost in Bosnia, too?

2. No diplomatic track in sight

The arc of the Syrian civil war seems pretty well set. These kinds of conflicts end either when one side triumphs, or when a third party intercedes to impose its will.

From the beginning, the conventional wisdom has been that the regime could not survive. That logic was partly driven by the fact that no other autocrats survived the Arab Spring. But it was also driven by what seemed like simple arithmetic: The regime looked increasingly weakened (subtraction) and the opposition seemed to be gaining in strength (addition). At some point, the situation would reach a tipping point, and Assad would be overthrown.

That hasn't happened. We have a military stalemate - or perhaps even a situation where the regime is gaining strength, while the opposition is losing it. Still, it appears that there's no military solution, and that only a political deal can end the conflict. Last year, the United Nations gave the diplomatic track a name: the "Geneva process." It has now been reenergized by the active participation of the United States under the leadership of Secretary of State John Kerry.

Whether the United States thinks this can work is irrelevant. What's important is that its strategy, at this point, is to get the Russians to force the regime and the rebels to the negotiating table. If Washington and Moscow can accomplish that, they just may be able to convince the warring parties to negotiate a political transition that eases Assad out, while bringing a coherent group of opposition elements to power. Such an accomplishment would go a long way to stopping the killing and preempting the need for U.S. military intervention.

But the odds that Geneva will succeed are long indeed. To paraphrase poet Elizabeth Barrett Browning, let me count the ways it could fail: Will the Russians really pressure Assad to leave? Will the Syrian dictator agree, particularly at a time when his regime is scoring military gains? Can anyone really speak authoritatively for the rebels inside and outside Syria? Will they risk a situation that leaves Assad in place - at least for a time? The paradox of Geneva 2.0 is that it could pave the way for the very situation the United States has tried to avoid. If (or when) diplomacy fails, it will be clear that there is only one remaining option to stop the bloodshed: military intervention.

Pressure will grow on the Obama administration to shoot, not talk.

3. The tough ladies are back

Individuals do matter in forging the U.S. government's response to an international crisis. And the ascension of Susan Rice as Obama's national security adviser and Samantha Power as America's envoy at the United Nations increases the odds of intervention in Syria.

Those two appointments have raised public expectations for the administration's foreign policy. Even I was surprised to see last week's Washington Post headline following the announcements: "Obama signals new approach on national security: A bigger U.S. role abroad." The implication was clear: There's a new sheriff in town.

I wouldn't dismiss this line so quickly. Rice is smart, tough, disciplined, and reportedly risk-averse on Syria. But she has a new job, and expectations for new and bolder initiatives are mounting. Combined with her own determination to make a difference, one of the pieces of the puzzle for intervention may have just fallen into place: She is closer to the president than any other foreign policy adviser. Should she join the chorus of those in the last term who pressed for bolder action (Hillary Clinton, David Petraeus), Obama will now have counsel to act from someone he truly respects and trusts.

It's lonely at the top. Sometimes you need close company to make tough decisions. Obama may now have it.

The other tough lady, Samantha Power, wrote a book about the Balkans (and other mass slaughters) called "A Problem From Hell." That of course describes Syria, too. This problem isn't going away. Indeed, it will likely get worse - before it gets even worse.

Too much blood has flowed in Syria to imagine a quick, negotiated settlement. The longer the conflict continues, the greater the odds that some new kinetic element - an Israeli-Syrian confrontation, massive use of chemical weapons, or some atrocity that surpasses previous horrors - will occur.

The steady drumbeat of death in Syria will increase the pressure on the United States to do something, anything, to stop the violence - even if it's out of good options for doing so. For better or worse, the Obama administration seems headed for military intervention in Syria, with all the risk and uncertainty that entails.

Miller, FP columnist, is vice president for new initiatives and a scholar at the Woodrow Wilson International Center for Scholars. His forthcoming book is titled "Can America Have Another Great President?"