From all indications, someone or some group is killing scientist associated with the Iranian nuclear program. At least four have been murdered, the most recent by a bomb attached to the victim's car by a motorcyclist; the killer escaped. These attacks seem sophisticated and one can only wonder at their genesis.
There are a number of implications if the source of the attacks is a nation. Wars do not discriminate, usually, and collateral damage always occurs. But there is no war and these are private citizens being murdered here. Nor are they being murdered for an ideology; they presumably are being murdered for their talents. This is a true advance in society.
Most fictional accounts of time travel describe a hero trying to right a wrong in history, usually by deflecting or eliminating the actions of an antagonist to some perceived good. Sometimes there are competing perceived "good"s, like "End of Eternity" by Asimov. But rarely is the enemy in history a talented individual in a talented chain.
One might argue that these scientists are part of a dangerous movement in Iran. But so, theoretically, is their grocer. Does this really mean that nations can legitimately target any and, presumably, every participant in an opposition political movement? What about their theorist, their spokesmen? What about their thinkers? What about their artists?