Herb wrote:

“The only thing that will work is prevention. Whatever the cost of prevention (loss of prestige, people, enduring enmity in the muslim world, bad breath) that cost will pale in comparison to the hell unleashed by a nuclear exchange.”

The prevention option may become more difficult with the Iranian acquisition of the SA-20 SAM system:

http://www.aviationweek.com/aw/generic/story.jsp?id=news/SAM12108.xml&headline=U.S. Sources: Iran Buying Russian SA-20s&channel=defense

There’s also a report of Iran moving troops and missiles into Eritrea:

http://informationdissemination.blogspot.com/2008/12/report-iran-deploys-troops-and-missiles.html

Which will doubtless complicate the situation there too.