For instance, if the US stations more troops in friendly states in the region and gives a Kennedy-esq statment [*] that, "It shall be the policy of this Nation to regard any nuclear missile launched from [Iran] against any nation in the [Middle East] as an attack by the [Iran] on the [vital interests of the] United States, requiring a full retaliatory response upon [Iran]" and be willing to dedicate lives and treasure for the policy, then an arms race could be prevented.

Agreed, but I'd go even further, stating to Iran in no uncertain terms that any nuclear detonation in which civilians are harmed anywhere in the world would be considered to have been orchistrated by Iran, and would therefore be tantamount to an attack by Iran on the vital interests of the United States, etc. This puts Iran in the unenviable position of having to police all the fundie middle eastern whackjobs in their "sphere of influence 9and a few over which they currently have no influence, e.g. North Korea). They want the bomb? Fine...but there are responsibilities that go along with the privilege. Mr. Armidinijad [sic], welcome to our MAD MAD world. Now, go forth and police your little corner of it.

It's amazing how far a little enlightned self-interest will go.