"Risks too high,...unless!"

".....Jordan has closer relations with the GCC member states than do any of the other countries bordering Syria -- Turkey, Iraq, Lebanon and Israel -- and is the only one that would consider allowing greater Saudi involvement within its borders. ...Jordan also shares a long border with Saudi Arabia, which could simplify access for financial and logistical support from the Gulf states to the rebels in Syria.....

Jordan's cooperation could provide Saudi Arabia a venue to extend its reach outside the Gulf and allows Riyadh to project greater influence into the Levant, something Iran has already done in Syria, southern Lebanon, and through Hamas and other groups in Israel. 

But the Jordanians do not want to see the Saudis turn their country into a proxy battleground against Iran....Despite Jordan's ideal strategic geographic placement for Saudi and GCC ambitions, the Hashemite Kingdom's historical relationship with Syria and domestic concerns present a unique set of challenges to increased action against Syria....... but Amman has been able to utilize the strength of its intelligence service -- the foundation of its relationships with the United States, Israel and the rest of the region -- to its advantage. Jordan cannot lead an offensive against the al Assad regime, but it can effectively facilitate one......

Mutual competition and mistrust notwithstanding, the current Syrian regime has proved useful to Jordan, though it pursued these actions for its own reasons. 

It has helped keep a check on the rise of Islamists in the region, especially since Jordan has a growing Muslim Brotherhood movement within its borders agitating for political reforms. 

Large-scale civil unrest following the dissolution of the Alawite regime would almost certainly spill over into Jordan, a country with a tenuous hold at best over its various Islamist groups.If the Jordanian monarchy fell, a contagion effect could spread to Saudi Arabia and the other GCC monarchies.

Jordan has maintained rhetorical support for GCC and Arab League resolutions on the Syrian uprising but has stopped short of backing direct foreign intervention, as was the case in Libya.

The Syrian regime currently appears to be maintaining control against the country's rebel movement.

 It does not appear likely that Jordan will openly support efforts to undermine the regime unless and until a credible foreign-backed military campaign against Syria begins.  

While Jordan's geographic proximity to Syria presents opportunities to Saudi Arabia and its allies, Amman stands to face serious retaliation if it boosted its support for the rebels, and there is a historical precedent for Syrian military action against Jordan..... 

As al Assad must contend with greater opportunities for Islamist insurgency within Syria's borders, Syrian jihadists could eventually join forces with jihadists in Jordan to launch attacks there as the Syrian regime begins to erode. Islamist insurgency within Jordan could trigger Israeli involvement, disrupting Jordan's strategic relationship with Israel.... 

Amman is not without other backers, however... Jordan can push back against increasing GCC pressure and defend its own interests by leaning on its relations with the United States and Turkey.......  Amman is unlikely to completely fall in line with GCC neighbors on openly calling for the ouster of the Syrian regime unless another foreign stakeholder with the military means and political will to lead the campaign enters the conflict."