Paris somehow conveniently forgets to spell out what they would in response to terror attacks by non-state actors. Its well known Tehran spawns jihad proxies (read hezbollah, Hamas, partly Al Qaeda too, etc) and could easily use one of these groups to wreck bio/chem or radioactive havoc. What then?? Can you launch attacks on Arab/persian cities on the basis of "alleged" links? I would in a heartbeat but its nice to see overindulged and US-protected EU grow up and grapple with adult questions for a while, eh?
When Western leaders talk about using nuclear weapons as retaliation, IT IS the official position.
While Iran can muse about it, Western leaders know they cannot joke around about using nukes.
One sure can.
The guilty countries are well known.
Knowing that they all will suffer certain massive damage to targets of the victim's choosing might dissuade even the insane.