NBC: Fears grow of Israel-Iran missile shootout

[Ruby the Liberal]

4. I may be misstating this

but I believe one of the concerns about a strike against Iran is that their development labs are so far underground that conventional bunker busters wouldn't be effective (wouldn't be able to get to the target).

I'll try to see if I can find that in print.

Edit - lots of sources. Heres one non-blog writeup:

Another critical difference from the prewar discussion in 2003 is the central role of Israel, which views the possibility of an Iranian nuclear weapon as a threat to its very existence and has warned that Iran’s nuclear facilities may soon be buried too deep for foreign bombers to reach.

http://www.nytimes.com/2012/02/22/world/middleeast/in-din-over-iran-echoes-of-iraq-war-news-analysis.html