http://www.haaretz.com/hasen/spages/808677.html

There is no conventional way for Israel (or the US, without massive strikes over time) to conventionally take out Iran's nukes.

Ground penetrators followed by small nukes could destroy bunkered facilities or make them unusable, and another benefit would be the object lesson that the Islamic threat is understood and will be dealt with.

A strike while Bush is in office would be a better bet than when a Democrat successor takes power. The likelihood of a Democratic Administration fully aiding Israel against Iran is IMO much less.