Will Israel bomb Iran?

Israel is now close to deciding whether it will attack Iran's nuclear installations, and if it does, whether it will use tactical nuclear weapons to penetrate their underground shields. This will be on the agenda of Ehud Olmert's talks in Washington. Apparently the urgency turns on Iran's acquisition of Russian air defense systems which will soon become operational. Given the long flights even Israeli planes would be exposed to being hit. If then a longer operation is needed the way might be opened for Iran to strike back in some way with consequences for, say, the price of oil. American permission may hinge on these calculations too. Can Israel deliver a fait accompli so swiftly that any later response by Iran can be construed as an "attack"? Oddly enough Olmert's domestic weakness may make him the ideal person to order the assault before he steps down. Of course, it would also be Bush's goodbye card as well.