Does Iran care about Mecca?
If you're referring to their version of Dear Leader "Imanutjob" himself, I seriously doubt it. But certainly the reverent muslims in that country do care, a lot. Will they hold HIM responsible if we nuke it in response to an attack on our soil by Imanutjob? Unknown. It might just spawn a mega JIHAD. So maybe a slightly restrained strike would be better initially. Instead of Mecca hit Medina or one of the other holy sites. THEN threaten Mecca. OR better yet, strike Teheran directly. Cut the head from the snake. While we're at it, send one or more into the area where we feel OBL is hiding. We've given the warlords there ample opportunity to give him up.