REUTERS/Nour Fourat

A Free Syrian Army fighter stands in a shooting position in Raqqa province, eastern Syria September 8, 2013.

Oil prices have climbed about 3.6% since the mere prospect of a Syria attack was raised at the end of August.

But in a new note, SocGen's Mike Wittner and former OPEC President Sadek Boussena say that while there would almost certainly be another jump should a strike occur, it probably won't be very great, and it probably can't last.

Indeed, it may even fall below current levels.

Here's Wittner:

If and when there is a limited US-led strike on Syria, Brent prices can go to $120-125 for a brief period – so there is another $5-10 of upside. However, in our base case, which has an 80% probability, there is no spillover that results in a real physical supply disruption in the MENA region. So within two weeks of the beginning of the military action, Brent will be back down where it was before this all started, at $110. It could even overshoot, and temporarily go lower, say to $105. But then the ongoing disruption in Libya would put a floor under prices and bring us back to $110 pretty quickly.

The reason is that fundamentals are not supportive of further advances.

Indeed, prior to the chemical attack being reported, the put/call ratio on the price of Brent was skewed  to the bearish side.

Here's Boussena:

When we look at the fundamentals, we have the growing prospect of US shale, we have significant risks to EM growth (currency depreciation), the possible financial impact of Fed tapering – all this quite bearish. 

Boussena does lay out the following spillover scenario that could push prices higher:

There is a larger risk with Syria even though it is not that important with respect to oil. 1) obviously if this spills into Iraq we could lose 2 mb/d; 2) bear in mind that the Gulf countries are participating by funding the rebels and perhaps in the future may themselves be at risk of retaliation via terrorism actions; and 3) most significantly, in Egypt there could be more tension, even though they have a strong army, and even though Egypt, Iraq and Saudi Arabia may not be directly impacted by a strike in Syria on the next day, week or even month, we could have much larger problems in these countries. In other words, we could see a knock-on impact in the following weeks or months.

But scenario will remain remote, Boussena says, as long as the strike is strategic and of limited duration.