Jordan was and as long as the royal family rule Jordan will be an ally to the west. The last king of Jordan was married to an american arab woman. Their (royal) culture is very western.
Remember the the king' s wife is Palestinian, and most probably done in order to pasify the majority of the population who are Palestinian.
Jordanian soldiers work very closely with us on the border, for the vast majority of the time. Remember Syria, who had a long internal war with the Muslim brotherhood, and they too struck hard against them. Egypt had/has the same problem.
As for the offer for a truce. I find it very hard that people took that seriously. Remember this type of offer is "valid" according to their religious teachings, in order to gain the upper hand..."hudna" comes to mind.
I would like to add, that AQ do not want an ally they want to get rid of the royal family, as they do in SA and any other regime that is not ...Islamic extreme.
Try this link
http://www.kinghussein.gov.jo/hashemites.html
Look at the family tree.