How exactly would an attack on Iran lead to WW3?
The most likely form of attack would come from Israel who would feel increasingly threatened by Iranian nuclear weapon production and would inevitably be backed by the US.
Israel strategic stirkes against Iranian powerplants suspected of producing weapons grade uranium/plutonium.
Outcry from Arabs states condemning such action.
Syria and other Arab states join forces against the 'infidels' and retaliate.
UN calls for calm in the region.
War escalates from strategic to civilian inevitable causalities, potentially chemical or biological warfare ensues
US back Israel along with UN/NATO countries.
Russia possibly become enthralled in the war due to being major suppliers of weaponry to the Arab league. Also politically, I doubt Russia or China would feel very comfortable allowing US led to gain control of a substantial amount of the worlds Oil reserves.
China could also be drawn into conflict due to communist ties with Russia however they are politically tied in with the US so which side they would take would be interesting. Either way it is likely they would sit on the fence and mop up what was left which being a world war would no doubt be very little.
The most likely account imo however would be a middle eastern war with each side having 'silent partners' who will sit back but provide the means to obliterate each other.
It's no secret that the Arab states want to wipe Israel off the map. Without nuclear weapons they have not had the means to do so, this however would hcange if/when Iran obtains them.
Scary times ahead I feel due to the massive unrest and instability in the region
