I would say that an intervention in Syria is possible. However, I would like to say that there is a lot of going on in regards to Syria.
In regards to Libya, there was no investigation into if the accusations against Gaddafi even held any weight. For example:
"Human rights organisations have cast doubt on claims of mass rape and other abuses perpetrated by forces loyal to Colonel Muammar Gaddafi, which have been widely used to justify Nato's war in Libya." (Amnesty questions claim that Gaddafi ordered rape as weapon of war - Africa - World - The Independent
"Still, the rebels have offered their own far-fetched claims, like mass rapes by loyalist troops issued tablets of Viagra. Although the rebels have not offered credible proof, that claim is nonetheless the basis of an investigation by the International Criminal Court." (http://www.nytimes.com/2011/08/24/wo...pagewanted=all
"There have been no confirmed cases of that; supposedly there are many African prisoners of war being held in Benghazi, but conveniently journalists are not allowed to see them.There are, however, African guest workers, poorly paid migrant labor, many of whom, unarmed, have been labeled mercenaries." (http://www.nytimes.com/2011/08/24/wo...pagewanted=all
In addition to this, there was little to no talk in the MSM about the rebels killing black Africans
"Across eastern Libya, rebel fighters and their supporters are detaining, intimidating and frequently beating African immigrants and black Libyans, accusing them of fighting as mercenaries on behalf of Kadafi, witnesses and human rights workers say.
In a few instances, rebels have executed suspected mercenaries captured in battle, according to Human Rights Watch and local Libyans." (Blacks In Libya | Libyan rebels accused of targeting blacks - Los Angeles Times
But the West did have a UN Mandate, thus they went in and bombed Libya and overthrew Gaddafi even though that last part was overstepping the UN mandate.
In Syria the situation is different as the US, France, and Britain are already aiding the Syrian rebels. According Philip Giraldi, a former CIA analyst, the Syrian rebels are being given weapons that are transported via "unmarked NATO airplanes," that "volunteers from the Libyan National Transitional Council" are being brought in to aid the rebels and that "French and British special forces trainers are on the ground, assisting the Syrian rebels while the CIA and U.S. Spec Ops are providing communications equipment and intelligence to assist the rebel cause, enabling the fighters to avoid concentrations of Syrian soldiers." (The American Conservative » NATO vs. Syria).
In addition to this, while the West is trying to get a UN mandate to possibly allow for intervention in Syria, they are ignoring the report that the Arab League observers came out with. Here are some excerpts:
The Mission determined that there is an armed entity that is not mentioned in the protocol. This development on the ground can undoubtedly be attributed to the excessive use of force by Syrian Government forces in response to protests that occurred before the deployment of the Mission demanding the fall of the regime. In some zones, this armed entity reacted by attacking Syrian security forces and citizens, causing the Government to respond with further violence. In the end, innocent citizens pay the price for those actions with life and limb. ...
Arab and foreign audiences of certain media organizations have questioned the Mission’s credibility because those organizations use the media to distort the facts. It will be difficult to overcome this problem unless there is political and media support for the Mission and its mandate. It is only natural that some negative incidents should occur as it conducts its activities because such incidents occur as a matter of course in similar missions....
In Homs, Idlib and Hama, the Observer Mission witnessed acts of violence being committed against Government forces and civilians that resulted in several deaths and injuries. Examples of those acts include the bombing of a civilian bus, killing eight persons and injuring others, including women and children, and the bombing of a train carrying diesel oil. In another incident in Homs, a police bus was blown up, killing two police officers. A fuel pipeline and some small bridges were also bombed.
The entire Arab League Syrian report can be seen here (http://www.columbia.edu/~hauben/Repo...er_Mission.pdf).
This has been completely ignored by the US and the Arab League as they are pushing for an intervention in Syria and this report does not line up with what they want. Thus, I think an intervention in Syria is possible.