Jordanians both like having our protection but worry we could open a front against Assad that would drag Jordan in to the war:
The United States has been slowly building a small military contingent on the Syrian border in Jordan as conflict rages in Syria. ...
The U.S. has plans to boost its small presence in neighboring Jordan, begun last year, to some 200 personnel - to prepare for a variety of scenarios, including a spillover of violence or the need to secure chemical weapons. ...
But some in Jordan were rattled when The Los Angeles Times last month quoted senior U.S. officials as saying up to 20,000 U.S. troops could be deployed, says analyst Fayez al Dwairi.
Our presence is just a headquarters element at this point, just in case we decide to intervene. I figured a division headquarters could command 50,000 considering we had three division headquarters commanding forces in Iraq and had north of 160,000 fighting there. And I did offer the caveat that the headquarters cold command 50,000 "if reinforced." So I've got that going for me.
Assuming this is just a forward command element with less capability than a full division headquarters, just 20,000 is the right number, it seems.
But that statement that we could deploy 20,000 is simply theoretical rather than a hint at things to come, I'd guess. The official simply stated the obvious--a headquarters of that capability could command and control 20,000 troops.
My guess is that if we go in, Jordan will already be dragged into the war in Syria. And note that Jordan is already taking steps to get involved on their own.