"... every attack abroad by the Iranian killer squads has the authorization of the highest echelons of government. It's only the appeasers who say otherwise. Government provides the training for the killers, the weapons via diplomatic pouches, the digital secure-phone links, the passports, the finance. Every operation abroad is laid before the foreign minister, the interior minister and the defense minister sitting on the National Supreme Security Council. It is authorized, sanctioned, on one condition only. The condition? There should be no smoking gun in Iran's hand ..."The above words are uttered by a Mossad station officer in the story.
The first issue is that this is quite a neat way of demonising your enemies using fiction. The second issue I have is on a more fundamental level; an event -- a bombing, an assassination -- has occurred, and one party points its fingers at somebody. When proof is asked for, it simply says the perpetrator has hidden its involvement so successfully that there is no smoking gun, and you'll just have to take their word for it. Sort of like the opposite of Occam's Razor: go for the most complicated, unprovable solution to a problem.