Syria: Nightmare scenario on horizon?

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It has been more than a year since Syria's uprising began, but unlike with Egypt, Tunisia or even Libya, there is no clear endgame.

What does the recent massacre there signal, how long can the regime of President Bashar al-Assad hang on and what should the U.S. do? Fawaz Gerges has been in and out of Syria three times in the last year, and he says it looks and feels like a civil war. Gerges, a professor at the London School of Economics and author of "Obama and the Middle East, the End of America's Moment," weighs in on the issue, in this edited interview with Fareed Zakaria from "Fareed Zakaria GPS."

ZAKARIA: What do you make of the recent brutal massacre? Does it tell us something about the regime? It feels like this is an attempt to really rule by a kind of terrible brutal example. What they are sending a signal throughout Syria is if any place tries something like this, you will be mowed down.

GERGES: The Houla massacre will not be the first and the last massacre. As you said, this is using fear as a tactic to terrorize the opposition and the population. My fear is that, in fact, the rock has set in. The significance of the slaughter in Houla is that it increases sector intentions between the minority-led government, the Alawite minority, President al-Assad, and the Sunni-dominated majority. What we are witnessing now, Fareed, is that the Syrian crisis, which was essentially a political crisis basically has turned into a protracted conflict.

Chaos has spread all over Syria. The Syrian government no longer has a monopoly on the use of force. It no longer controls many areas of Syria. And I believe that the writing is on the wall. We're going to see more and more violence in the next few weeks and next few months. My fear is that the protracted armed conflict could easily plunge Syria into all-out sectarian strife. This is the nightmare scenario in Syria.

Related: Fareed's Take: The case against intervention

ZAKARIA: For a year, while many people believed and predicted that the al-Assad regime would fall quickly, you argued the opposite: you said that the regime did not seem likely to fall for a variety of reasons. You said that there were no defections among the military apparatus. Do you think that with this new situation, the regime can hold on?

GERGES: There are so many unknown variables. The first unknown variable is basically costs of the sanctions that have been imposed on Syria in the last year or so. As you know, America is waging a war by other means, an economic war. A psychological war. Can Syria survive another harsh winter in terms of Syria needs gas, cooking oil, food.

Secondly, we don't know what's happening within the security apparatus - the extent of tensions between the military and the security apparatus. But the reality is the security forces in Syria have proved to be much more resilient than many observers and many Western governments have believed. That the Syrian government, the al-Assad regime, despite everything that you have heard, retains a critical base of support. You have many Syrians, millions of Syrians, still supporting this particular regime.

And more importantly, the Syrian crisis has been caught in a fierce regional struggle between the Iranian camp on the one hand and the Saudi camp on the other hand. Syria is receiving tremendous support from both Iraq, America's ally, and Iran as well. Not to mention that the U.N. Security Council has been neutralized by a double Russian and Chinese veto.

So internally, regionally and internationally, it seems to me that this is a highly complex and protracted conflict, and no, far from being his days numbered, I think al-Assad will be with us for a while, unfortunately for the Syrian people.

ZAKARIA: Can I get you to expand on one thing you said there? You mentioned that this has turned into a sectarian, regional struggle, with the Saudi Arabia funding what is becoming essentially a Sunni insurgency against the al-Assad regime - al-Assad being an Alawite, which is essentially a Shiite regime, supported by Iran but also by Iraq. So our ally, the Iraqi government, Prime Minister Nouri al-Maliki, is supporting the Syrian regime. Is that correct?

GERGES: It's absolutely correct. In fact, I would argue that the Tehran-Baghdad road has become the lifeline of the al-Assad regime. Syria is receiving tremendous support, material support, political support, and even military support, and Iraq sees itself as basically part of the alliance against the so-called the Turkish, Saudi, Sunni-dominated alliance, but my fear is that what the Houla massacre has done, it has poured gasoline on a raging fire, and my fear is that the essentially political conflict in Syria could easily expand into a sectarian strife, destroying not only Syria, but also neighboring countries like Lebanon and Jordan and spilling over into Iraq as well.

ZAKARIA: What do you think the United States should do? There are people advocating military intervention. Mitt Romney is now saying the president should take a firmer stand, whatever that means. What do you think we should do?

GERGES: It's extremely difficult to watch the massacres like this Houla massacre and remain neutral. I really feel sometimes being morally complicit in saying that military intervention in Syria will most likely exacerbate an already dangerous situation. In fact, I would argue that military intervention in Syria will likely plunge Syria faster into all-out sectarian strife. Not to mention the fact that regional powers will come in, Hezbollah and Iran. This will turn into a region-wide conflict. And there is no Security Council resolution to intervene in Syria.

I think the Obama administration is doing the right thing. That is, trying to economically strangle the al-Assad regime. The only point here is that we know from the history of sanctions, to what extent have the sanctions exacted a heavy toll on the al-Assad regime? How long can the al-Assad regime basically maintain its posture, given the fact it's receiving support from its regional allies, Iran and Iraq, and also trade with Lebanon and Jordan and Turkey? So, the reality is all options are bad. The menu of choice is very limited. I don't think the Obama administration has the luxury to entertain military intervention in Syria. This is really quite what I call the nuclear option for the United States and Syria and its neighbors as well.